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29 Sep 2023 at 01:52
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Bibliography on: Microbiome Project(s)


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RJR: Recommended Bibliography 29 Sep 2023 at 01:52 Created: 

Microbiome Project(s)

For many multicellular organisms, a microscopic study shows that microbial cells outnumber host cells by perhaps ten to one. Until recently, these abundant communities of host-associated microbes were largely unstudied, often for lack of analytical tools or conceptual frameworks. The advent of new tools is rendering visible this previously ignored biosphere and the results have been startling. Many facets of host biology have proven to be profoundly affected by the associated microbiomes. As a result, several large-scale projects — such as the Human Microbiome Project — have been undertaken to jump start an understanding of this critical component of the biosphere.

Created with PubMed® Query: "microbiome project" NOT pmcbook NOT ispreviousversion

Citations The Papers (from PubMed®)


RevDate: 2023-09-25

Duan Z, Fu J, Zhang F, et al (2023)

The association between BMI and serum uric acid is partially mediated by gut microbiota.

Microbiology spectrum [Epub ahead of print].

Obesity is a risk factor for the development of hyperuricemia, both of which were related to gut microbiota. However, whether alterations in the gut microbiota lie in the pathways mediating obesity's effects on hyperuricemia is less clear. Body mass index (BMI) and serum uric acid (SUA) were separately important indicators of obesity and hyperuricemia. Our study aims to investigate whether BMI-related gut microbiota characteristics would mediate the association between BMI and SUA levels. A total of 6,280 participants from Guangdong Gut Microbiome Project were included in this study. Stool samples were collected for 16S rRNA gene sequencing. The results revealed that BMI was significantly and positively associated with SUA. Meanwhile, BMI was significantly associated with the abundance of 102 gut microbial genera, 16 of which were also significantly associated with SUA. The mediation analysis revealed that the association between BMI and SUA was partially mediated by the abundance of Proteobacteria (proportion mediated: 0.94%, P < 0.05). At the genus level, 25 bacterial genera, including Ralstonia, Oscillospira, Faecalibacterium, etc., could also partially mediate the association of BMI with SUA (the highest proportion is mediated by Ralstonia, proportion mediated: 2.76%, P < 0.05). This study provided evidence for the associations among BMI, gut microbiota, and SUA, and the mediation analysis suggested that the association of BMI with SUA was partially mediated by the gut microbiota. IMPORTANCE Using 16S rRNA sequencing analysis, local interpretable machine learning technique analysis and mediation analysis were used to explore the association between BMI with SUA, and the mediating effects of gut microbial dysbiosis in the association were investigated.

RevDate: 2023-09-18

Hayer SS, Hwang S, JB Clayton (2023)

Antibiotic-induced gut dysbiosis and cognitive, emotional, and behavioral changes in rodents: a systematic review and meta-analysis.

Frontiers in neuroscience, 17:1237177.

There are previous epidemiological studies reporting associations between antibiotic use and psychiatric symptoms. Antibiotic-induced gut dysbiosis and alteration of microbiota-gut-brain axis communication has been proposed to play a role in this association. In this systematic review and meta-analysis, we reviewed published articles that have presented results on changes in cognition, emotion, and behavior in rodents (rats and mice) after antibiotic-induced gut dysbiosis. We searched three databases-PubMed, Web of Science, and SCOPUS to identify such articles using dedicated search strings and extracted data from 48 articles. Increase in anxiety and depression-like behavior was reported in 32.7 and 40.7 percent of the study-populations, respectively. Decrease in sociability, social novelty preference, recognition memory and spatial cognition was found in 18.1, 35.3, 26.1, and 62.5 percent of the study-populations, respectively. Only one bacterial taxon (increase in gut Proteobacteria) showed statistically significant association with behavioral changes (increase in anxiety). There were no consistent findings with statistical significance for the potential biomarkers [Brain-derived neurotrophic factor (BDNF) expression in the hippocampus, serum corticosterone and circulating IL-6 and IL-1β levels]. Results of the meta-analysis revealed a significant association between symptoms of negative valence system (including anxiety and depression) and cognitive system (decreased spatial cognition) with antibiotic intake (p < 0.05). However, between-study heterogeneity and publication bias were statistically significant (p < 0.05). Risk of bias was evaluated to be high in the majority of the studies. We identified and discussed several reasons that could contribute to the heterogeneity between the results of the studies examined. The results of the meta-analysis provide promising evidence that there is indeed an association between antibiotic-induced gut dysbiosis and psychopathologies. However, inconsistencies in the implemented methodologies make generalizing these results difficult. Gut microbiota depletion using antibiotics may be a useful strategy to evaluate if and how gut microbes influence cognition, emotion, and behavior, but the heterogeneity in methodologies used precludes any definitive interpretations for a translational impact on clinical practice.

RevDate: 2023-09-01

Corewyn LC, Kelaita MA, Nollman J, et al (2023)

Hematology and blood biochemistry in a declining population of mantled howler monkeys (Alouatta palliata palliata) at La Pacifica, Costa Rica.

Journal of medical primatology [Epub ahead of print].

BACKGROUND: Alouatta palliata palliata are an ecologically flexible howler monkey subspecies that has recently been relisted as Endangered. Populations are declining through much of the subspecies' range, including at our study site at La Pacifica, Costa Rica. Our objectives were to screen blood hematology and biochemistry samples collected from this wild population to elucidate their baseline health.

METHODS: We collected blood samples from 38 adult individuals from across the study site and analyzed 13 hematology and 14 biochemistry parameters.

RESULTS: Most hematology and blood biochemistry parameter values were similar between males and females. However, mean hemoglobin was significantly lower, and mean white blood cell count was significantly higher in females; and mean calcium and mean creatinine were significantly lower in females compared to males.

CONCLUSIONS: Overall, the La Pacifica population appeared healthy based on the blood parameters analyzed from sampled individuals. Our results were also largely consistent with published data available from other populations of A. p. palliata, and with reference values for captive Alouatta caraya.

RevDate: 2023-08-29

Koo H, CD Morrow (2023)

Identification of donor Bacteroides vulgatus genes encoding proteins that correlate with early colonization following fecal transplant of patients with recurrent Clostridium difficile.

Scientific reports, 13(1):14112.

Due to suppressive antibiotics, patients with recurrent Clostridium difficile have gut microbial communities that are devoid of most commensal microbes. Studies have shown that most of the failures using fecal microbe transplantation (FMT) for recurrent C. difficile occur during the first 4 weeks following transplantation. To identify features of donor Bacteroides vulgatus that lead to early colonization, we used two data sets that collected fecal samples from recipients at early times points post FMT. The first analysis used the shotgun metagenomic DNA sequencing data set from Aggarwala et al. consisting of 7 FMT donors and 13 patients with recurrent C. difficile with fecal samples taken as early as 24 h post FMT. We identified 2 FMT donors in which colonization of recipients by donor B. vulgatus was detected as early as 24 h post FMT. We examined a second data set from Hourigan et al. that collected fecal samples from C. difficile infected children and identified 1 of 3 FMT that also had early colonization of the donor B. vulgatus. We found 19 genes out of 4911 encoding proteins were unique to the 3 donors that had early colonization. A gene encoding a putative chitobiase was identified that was in a gene complex that had been previously identified to enhance colonization in mice. A gene encoding a unique fimbrillin (i.e., pili) family protein and 17 genes encoding hypothetical proteins were also specific for early colonizing donors. Most of the genes encoding hypothetical proteins had neighboring genes that encoded proteins involved in mobilization or transposition. Finally, analysis of 42 paired fecal samples from the human microbiome project (HMP) found no individuals had all 19 genes while 2 individuals had none of the 19 genes. Based on the results from our study, consideration should be given to the screening of FMT donors for these B. vulgatus genes found to enhance early colonization that would be of benefit to promote colonization following FMT.

RevDate: 2023-08-29

Farmer N, Maki KA, Barb JJ, et al (2023)

Geographic social vulnerability is associated with the alpha diversity of the human microbiome.

mSystems [Epub ahead of print].

The human microbiome ecosystems living within the human body are exposed to exogenous foreign substances from the various environments that humans live within. Therefore, dynamics between microbes and human hosts can be influenced by environmental changes, which potentially impact microbiome composition and diversity. Geographic area, as a microbiome-relevant environmental factor, has been well reported. Human geography, however, is often linked to socioeconomic status, racial and ethnic population enclaves, and disparities in area disadvantage. Potential mechanisms linking the microbiome to factors tied to area disadvantage include household crowding, use of public transportation, and lack of exposure to biodiverse natural environments. Through an analysis of data from the Human Microbiome Project including healthy adults who reported residential area information at the time of microbiome sampling (n = 201), we found a significant relationship between the social vulnerability index (SVI), as a measure of area disadvantage, and multiple alpha diversity measures across oral, airways, and urogenital sites when controlling for age, gender, and body mass index. With regard to race/ethnicity, we found significant mediation by SVI score to explain racial/ethnic differences in urogenital microbiome diversity in females. Our results highlight the importance of considering environmental variables such as area social vulnerability as a variable of interest in microbiome studies within healthy individuals and suggest a potential role to explain urogenital race/ethnicity differences. Future studies including a diverse, representative community-based population, more precise residential location, and inclusion of related risk factors such as dietary intake, are needed to further understand the implications of these results. IMPORTANCE As a risk factor for conditions related to the microbiome, understanding the role of SVI on microbiome diversity may assist in identifying public health implications for microbiome research. Here we found, using a sub-sample of the Human Microbiome Project phase 1 cohort, that SVI was linked to microbiome diversity across body sites and that SVI may influence race/ethnicity-based differences in diversity. Our findings, build on the current knowledge regarding the role of human geography in microbiome research, suggest that measures of geographic social vulnerability be considered as additional contextual factors when exploring microbiome alpha diversity.

RevDate: 2023-08-28

Li W, Mirone J, Prasad A, et al (2023)

Orthogonal outlier detection and dimension estimation for improved MDS embedding of biological datasets.

Frontiers in bioinformatics, 3:1211819.

Conventional dimensionality reduction methods like Multidimensional Scaling (MDS) are sensitive to the presence of orthogonal outliers, leading to significant defects in the embedding. We introduce a robust MDS method, called DeCOr-MDS (Detection and Correction of Orthogonal outliers using MDS), based on the geometry and statistics of simplices formed by data points, that allows to detect orthogonal outliers and subsequently reduce dimensionality. We validate our methods using synthetic datasets, and further show how it can be applied to a variety of large real biological datasets, including cancer image cell data, human microbiome project data and single cell RNA sequencing data, to address the task of data cleaning and visualization.

RevDate: 2023-08-28

Gois MFB, Fernández-Pato A, Huss A, et al (2023)

Impact of occupational pesticide exposure on the human gut microbiome.

Frontiers in microbiology, 14:1223120.

The rising use of pesticides in modern agriculture has led to a shift in disease burden in which exposure to these chemicals plays an increasingly important role. The human gut microbiome, which is partially responsible for the biotransformation of xenobiotics, is also known to promote biotransformation of environmental pollutants. Understanding the effects of occupational pesticide exposure on the gut microbiome can thus provide valuable insights into the mechanisms underlying the impact of pesticide exposure on health. Here we investigate the impact of occupational pesticide exposure on human gut microbiome composition in 7198 participants from the Dutch Microbiome Project of the Lifelines Study. We used job-exposure matrices in combination with occupational codes to retrieve categorical and cumulative estimates of occupational exposures to general pesticides, herbicides, insecticides and fungicides. Approximately 4% of our cohort was occupationally exposed to at least one class of pesticides, with predominant exposure to multiple pesticide classes. Most participants reported long-term employment, suggesting a cumulative profile of exposure. We demonstrate that contact with insecticides, fungicides and a general "all pesticides" class was consistently associated with changes in the gut microbiome, showing significant associations with decreased alpha diversity and a differing beta diversity. We also report changes in the abundance of 39 different bacterial taxa upon exposure to the different pesticide classes included in this study. Together, the extent of statistically relevant associations between gut microbial changes and pesticide exposure in our findings highlights the impact of these compounds on the human gut microbiome.

RevDate: 2023-08-26

Zhang F, Zhang X, Fu J, et al (2023)

Sex- and Age-Dependent Associations between Parabacteroides and Obesity: Evidence from Two Population Cohort.

Microorganisms, 11(8): pii:microorganisms11082087.

Parabacteroides levels are reported to be low in obese individuals, and this genus has shown an anti-obesity capacity in animal studies. Nevertheless, the relationship between Parabacteroides and obesity in different subpopulations, e.g., with respect to age and sex, and its association with subsequent weight change have rarely been explored. The cross-sectional associations of Parabacteroides genus- and species-level OTU abundance with obesity were explored in the Guangdong Gut Microbiome Project (GGMP), which included 5843 adults, and replicated in the Guangzhou Nutrition and Health Study (GNSH), which included 1637 individuals. Furthermore, we assessed the prospective associations of Parabacteroides and its main OTUs' abundance with the subsequent changes in body mass index (BMI) in the GNSH. We found that Parabacteroides was inversely associated with obesity among females and participants aged 40-69 years in the GGMP and the replicated cohort in the GNSH. After a 3-year follow-up, there was no significant correlation between Parabacteroides and the subsequent changes in BMI. However, Seq4172 (P. johnsonii) showed a negative correlation with subsequent BMI changes in the female and middle-aged (40-69 years) subpopulations. Overall, our results indicate that Parabacteroides have an inverse relationship with obesity and that Seq4172 (P. johnsonii) have a negative association with subsequent changes in BMI among females and middle-aged populations in perspective analyses.

RevDate: 2023-08-25

Singh S, Singh S, Lukas SB, et al (2023)

Long-term agro-management strategies shape soil bacterial community structure in dryland wheat systems.

Scientific reports, 13(1):13929.

Soil microbes play a crucial role in soil organic matter decomposition and nutrient cycling and are influenced by management practices. Therefore, quantifying the impacts of various agricultural management practices on soil microbiomes and their activity is crucial for making informed management decisions. This study aimed to assess the impact of various management systems on soil bacterial abundance and diversity, soil enzyme activities and carbon mineralization potential in wheat-based systems. To accomplish this, soil samples from 0 to 15 cm depth were collected from ongoing long-term field trials in eastern Oregon region under wheat (Triticum aestivum L.)-fallow (WF), WF with different tillage (WT), wheat-pea (Pisum sativum L.) (WP), WF under different crop residue management (CR) and natural undisturbed/unmanaged grassland pasture (GP). These trials consisted of an array of treatments like tillage intensities, nitrogen rates, organic amendments, and seasonal residue burning. This study was a part of the Soil Health Institute's North American Project to Evaluate Soil Health measurements (NAPESHM). Bacterial community structure was determined using amplicon sequencing of the V4 region of 16SrRNA genes and followed the protocols of the Earth Microbiome Project. In addition, extracellular enzyme activities, and carbon mineralization potential (1d-CO2) were measured. Among different trials, 1d-CO2 in WT, WP, and CR studies averaged 53%, 51% and 87% lower than GP systems, respectively. Enzyme activities were significantly greater in GP compared to the other managements and followed similar trend as respiration. We observed higher evenness in GP and higher richness in spring residue burning treatment of CR study. Our results indicated that species evenness is perhaps a better indicator of soil health in comparison to other indices in dryland wheat systems.

RevDate: 2023-08-24

Golovko G, Khanipov K, Reyes V, et al (2023)

Identification of multivariable Boolean patterns in microbiome and microbial gene composition data.

Bio Systems pii:S0303-2647(23)00182-X [Epub ahead of print].

Virtually every biological system is governed by complex relations among its components. Identifying such relations requires a rigorous or heuristics-based search for patterns among variables/features of a system. Various algorithms have been developed to identify two-dimensional (involving two variables) patterns employing correlation, covariation, mutual information, etc. It seems obvious, however, that comprehensive descriptions of complex biological systems need also to include more complicated multivariable relations, which can only be described using patterns that simultaneously embrace 3, 4, and more variables. The goal of this manuscript is to (a) introduce a novel type of associations (multivariable Boolean patterns) that can be manifested between features of complex systems but cannot be identified (described) by traditional pair-vise metrics; (b) propose patterns classification method, and (c) provide a novel definition of the pattern's strength (pattern's score) able to accommodate heterogeneous multi-omics data. To demonstrate the presence of such patterns, we performed a search for all possible 2-, 3-, and 4-dimensional patterns in historical data from the Human Microbiome Project (15 body sites) and collection of H. pylori genomes associated with gastric ulcers, gastritis, and duodenal ulcers. In all datasets under consideration, we were able to identify hundreds of statistically significant multivariable patterns. These results suggest that such patterns can be common in microbial genomics/microbiomics systems.

RevDate: 2023-08-12

Dong H, D Ming (2023)

A Comprehensive Self-Resistance Gene Database for Natural-Product Discovery with an Application to Marine Bacterial Genome Mining.

International journal of molecular sciences, 24(15): pii:ijms241512446.

In the world of microorganisms, the biosynthesis of natural products in secondary metabolism and the self-resistance of the host always occur together and complement each other. Identifying resistance genes from biosynthetic gene clusters (BGCs) helps us understand the self-defense mechanism and predict the biological activity of natural products synthesized by microorganisms. However, a comprehensive database of resistance genes is still lacking, which hinders natural product annotation studies in large-scale genome mining. In this study, we compiled a resistance gene database (RGDB) by scanning the four available databases: CARD, MIBiG, NCBIAMR, and UniProt. Every resistance gene in the database was annotated with resistance mechanisms and possibly involved chemical compounds, using manual annotation and transformation from the resource databases. The RGDB was applied to analyze resistance genes in 7432 BGCs in 1390 genomes from a marine microbiome project. Our calculation showed that the RGDB successfully identified resistance genes for more than half of the BGCs, suggesting that the database helps prioritize BGCs that produce biologically active natural products.

RevDate: 2023-08-04

Su Q, Jin C, Bo Z, et al (2023)

Association between gut microbiota and gastrointestinal cancer: a two-sample bi-directional Mendelian randomization study.

Frontiers in microbiology, 14:1181328.

BACKGROUND: The gut microbiome is closely related to gastrointestinal (GI) cancer, but the causality of gut microbiome with GI cancer has yet to be fully established. We conducted this two-sample Mendelian randomization (MR) study to reveal the potential causal effect of gut microbiota on GI cancer.

MATERIALS AND METHODS: Summary-level genetic data of gut microbiome were derived from the MiBioGen consortium and the Dutch Microbiome Project. Summary statistics of six GI cancers were drawn from United Kingdom Biobank. Inverse-variance-weighted (IVW), MR-robust adjusted profile score (MR-RAPS), and weighted-median (WM) methods were used to evaluate the potential causal link between gut microbiota and GI cancer. In addition, we performed sensitivity analyses and reverse MR analyses.

RESULTS: We identified potential causal associations between 21 bacterial taxa and GI cancers (values of p < 0.05 in all three MR methods). Among them, phylum Verrucomicrobia (OR: 0.17, 95% CI: 0.05-0.59, p = 0.005) retained a strong negative association with intrahepatic cholangiocarcinoma after the Bonferroni correction, whereas order Bacillales (OR: 1.67, 95% CI: 1.23-2.26, p = 0.001) retained a strong positive association with pancreatic cancer. Reverse MR analyses indicated that GI cancer was associated with 17 microbial taxa in all three MR methods, among them, a strong inverse association between colorectal cancer and family Clostridiaceae1 (OR: 0.91, 95% CI: 0.86-0.96, p = 0.001) was identified by Bonferroni correction.

CONCLUSION: Our study implicates the potential causal effects of specific microbial taxa on GI cancer, potentially providing new insights into the prevention and treatment of GI cancer through specific gut bacteria.

RevDate: 2023-07-02
CmpDate: 2023-06-30

Seabourn PS, Weber DE, Spafford H, et al (2023)

Aedes albopictus microbiome derives from environmental sources and partitions across distinct host tissues.

MicrobiologyOpen, 12(3):e1364.

The mosquito microbiome consists of a consortium of interacting microorganisms that reside on and within culicid hosts. Mosquitoes acquire most of their microbial diversity from the environment over their life cycle. Once present within the mosquito host, the microbes colonize distinct tissues, and these symbiotic relationships are maintained by immune-related mechanisms, environmental filtering, and trait selection. The processes that govern how environmental microbes assemble across the tissues within mosquitoes remain poorly resolved. We use ecological network analyses to examine how environmental bacteria assemble to form bacteriomes among Aedes albopictus host tissues. Mosquitoes, water, soil, and plant nectar were collected from 20 sites in the Mānoa Valley, Oahu. DNA was extracted and associated bacteriomes were inventoried using Earth Microbiome Project protocols. We find that the bacteriomes of A. albopictus tissues were compositional taxonomic subsets of environmental bacteriomes and suggest that the environmental microbiome serves as a source pool that supports mosquito microbiome diversity. Within the mosquito, the microbiomes of the crop, midgut, Malpighian tubules, and ovaries differed in composition. This microbial diversity partitioned among host tissues formed two specialized modules: one in the crop and midgut, and another in the Malpighian tubules and ovaries. The specialized modules may form based on microbe niche preferences and/or selection of mosquito tissues for specific microbes that aid unique biological functions of the tissue types. A strong niche-driven assembly of tissue-specific microbiotas from the environmental species pool suggests that each tissue has specialized associations with microbes, which derive from host-mediated microbe selection.

RevDate: 2023-08-07
CmpDate: 2023-07-31

Adelfio M, Bonzanni M, Callen GE, et al (2023)

A physiologically relevant culture platform for long-term studies of in vitro gingival tissue.

Acta biomaterialia, 167:321-334.

There is a clinical need to understand the etiologies of periodontitis, considering the growing socio-economic impact of the disease. Despite recent advances in oral tissue engineering, experimental approaches have failed to develop a physiologically relevant gingival model that combines tissue organization with salivary flow dynamics and stimulation of the shedding and non-shedding oral surfaces. Herein, we develop a dynamic gingival tissue model composed of a silk scaffold, replicating the cyto-architecture and oxygen profile of the human gingiva, along with a saliva-mimicking medium that reflected the ionic composition, viscosity, and non-Newtonian behavior of human saliva. The construct was cultured in a custom designed bioreactor, in which force profiles on the gingival epithelium were modulated through analysis of inlet position, velocity and vorticity to replicate the physiological shear stress of salivary flow. The gingival bioreactor supported the long-term in vivo features of the gingiva and improved the integrity of the epithelial barrier, critical against the invasion of pathogenic bacteria. Furthermore, the challenge of the gingival tissue with P. gingivalis lipopolysaccharide, as an in vitro surrogate for microbial interactions, indicated a greater stability of the dynamic model in maintaining tissue homeostasis and, thus, its applicability in long-term studies. The model will be integrated into future studies with the human subgingival microbiome to investigate host-pathogen and host-commensal interactions. STATEMENT OF SIGNIFICANCE: The major societal impact of human microbiome had reverberated up to the establishment of the Common Fund's Human Microbiome Project, that has the intent of studying the role of microbial communities in human health and diseases, including periodontitis, atopic dermatitis, or asthma and inflammatory bowel disease. In addition, these chronic diseases are emergent drivers of global socioeconomic status. Not only common oral diseases have been shown to be directly correlated with several systemic conditions, but they are differentially impacting some racial/ethnic and socioeconomic groups. To address this growing social disparity, the development of in vitro gingival model would provide a time and cost-effective experimental platform, able to mimic the spectrum of periodontal disease presentation, for the identification of predictive biomarkers for early-stage diagnosis.

RevDate: 2023-06-17

Bar K, Litera-Bar M, B Sozańska (2023)

Bacterial Microbiota of Asthmatic Children and Preschool Wheezers' Airways-What Do We Know?.

Microorganisms, 11(5):.

Asthma is the most chronic pulmonary disease in pediatric population, and its etiopathology still remains unclear. Both viruses and bacteria are suspected factors of disease development and are responsible for its exacerbation. Since the launch of The Human Microbiome Project, there has been an explosion of research on microbiota and its connection with various diseases. In our review, we have collected recent data about both upper- and lower-airway bacterial microbiota of asthmatic children. We have also included studies regarding preschool wheezers, since asthma diagnosis in children under 5 years of age remains challenging due to the lack of an objective tool. This paper indicates the need for further studies of microbiome and asthma, as in today's knowledge, there is no particular bacterium that discriminates the asthmatics from the healthy peers and can be used as a potential biological factor in the disease prevalence and treatment.

RevDate: 2023-06-02

Addison S, Armstrong C, Wigley K, et al (2023)

What matters most? Assessment of within-canopy factors influencing the needle microbiome of the model conifer, Pinus radiata.

Environmental microbiome, 18(1):45.

The assembly and function of the phyllosphere microbiome is important to the overall fitness of plants and, thereby, the ecosystems they inhabit. Presently, model systems for tree phyllosphere microbiome studies are lacking, yet forests resilient to pests, diseases, and climate change are important to support a myriad of ecosystem services impacting from local to global levels. In this study, we extend the development of model microbiome systems for trees species, particularly coniferous gymnosperms, by undertaking a structured approach assessing the phyllosphere microbiome of Pinus radiata. Canopy sampling height was the single most important factor influencing both alpha- and beta-diversity of bacterial and fungal communities (p < 0.005). Bacterial and fungal phyllosphere microbiome richness was lowest in samples from the top of the canopy, subsequently increasing in the middle and then bottom canopy samples. These differences maybe driven by either by (1) exchange of microbiomes with the forest floor and soil with the lower foliage, (2) strong ecological filtering in the upper canopy via environmental exposure (e.g., UV), (3) canopy density, (4) or combinations of factors. Most taxa present in the top canopy were also present lower in tree; as such, sampling strategies focussing on lower canopy sampling should provide good overall phyllosphere microbiome coverage for the tree. The dominant phyllosphere bacteria were Alpha-proteobacteria (Rhizobiales and Sphingomonas) along with Acidobacteria Gp1. However, the P. radiata phyllosphere microbiome samples were fungal dominated. From the top canopy samples, Arthoniomycetes and Dothideomycetes were highly represented, with abundances of Arthoniomycetes then reducing in lower canopy samples whilst abundances of Ascomycota increased. The most abundant fungal taxa were Phaeococcomyces (14.4% of total reads) and Phaeotheca spp. (10.38%). A second-order effect of canopy sampling direction was evident in bacterial community composition (p = 0.01); these directional influences were not evident for fungal communities. However, sterilisation of needles did impact fungal community composition (p = 0.025), indicating potential for community differences in the endosphere versus leaf surface compartments. Needle age was only important in relation to bacterial communities, but was canopy height dependant (interaction p = 0.008). By building an understanding of the primary and secondary factors related to intra-canopy phyllosphere microbiome variation, we provide a sampling framework to either explicitly minimise or capture variation in needle collection to enable ongoing ecological studies targeted at inter-canopy or other experimental levels.

RevDate: 2023-06-29
CmpDate: 2023-06-16

Chow EWL, Pang LM, Y Wang (2023)

Impact of the host microbiota on fungal infections: New possibilities for intervention?.

Advanced drug delivery reviews, 198:114896.

Many human fungal pathogens are opportunistic. They are primarily benign residents of the human body and only become infectious when the host's immunity and microbiome are compromised. Bacteria dominate the human microbiome, playing an essential role in keeping fungi harmless and acting as the first line of defense against fungal infection. The Human Microbiome Project, launched by NIH in 2007, has stimulated extensive investigation and significantly advanced our understanding of the molecular mechanisms governing the interaction between bacteria and fungi, providing valuable insights for developing future antifungal strategies by exploiting the interaction. This review summarizes recent progress in this field and discusses new possibilities and challenges. We must seize the opportunities presented by researching bacterial-fungal interplay in the human microbiome to address the global spread of drug-resistant fungal pathogens and the drying pipelines of effective antifungal drugs.

RevDate: 2023-06-14

Dai H, Hou T, Wang Q, et al (2023)

Causal relationships between the gut microbiome, blood lipids, and heart failure: a Mendelian randomization analysis.

European journal of preventive cardiology pii:7169369 [Epub ahead of print].

BACKGROUND: Studies have linked gut microbiome and heart failure (HF). However, their causal relationships and potential mediating factors have not been well defined.

AIMS: To investigate the causal relationships between the gut microbiome and HF and the mediating effect of potential blood lipids by using genetics.

METHOD: We performed a bidirectional and mediation Mendelian randomization (MR) study using summary statistics from the genome-wide association studies of gut microbial taxa (Dutch Microbiome Project, n = 7,738), blood lipids (UK Biobank, n = 115,078), and a meta-analysis of HF (115,150 cases and 1,550,331 controls). We applied the inverse-variance weighted estimation method as the primary method, with several other estimators as complementary methods. The multivariable MR approach based on Bayesian model averaging (MR-BMA) was used to prioritize the most likely causal lipids.

RESULTS: Six microbial taxa are suggestively associated with HF causally. The most significant taxon was the species Bacteroides dorei (odds ratio = 1.059, 95% confidence interval [CI] = 1.022 - 1.097, P value = 0.0017). The MR-BMA analysis showed that apolipoprotein B (ApoB) was the most likely causal lipid for HF (the marginal inclusion probability = 0.717, P value = 0.005). The mediation MR analysis showed that ApoB mediated the causal effects of species Bacteroides dorei on HF (proportion mediated = 10.1%, 95% CI = 0.2% - 21.6%, P value = 0.031).

CONCLUSION: The study suggested a causal relationship between specific gut microbial taxa and HF and that ApoB might mediate this relationship as the primary lipid determinant of HF.

RevDate: 2023-07-03
CmpDate: 2023-07-03

Wang J, Pan Z, Yu J, et al (2023)

Global assembly of microbial communities.

mSystems, 8(3):e0128922.

Different habitats harbor different microbial communities with elusive assembly mechanisms. This study comprehensively investigated the global assembly mechanisms of microbial communities and effects of community-internal influencing factors using the Earth Microbiome Project (EMP) data set. We found that deterministic and stochastic processes contribute approximately equally to global microbial community assembly, and, specifically, deterministic processes generally play a major role in free-living and plant-associated (but not plant corpus) environments, while stochastic processes are the major contributor in animal-associated environments. In contrast with the assembly of microorganisms, the assembly of functional genes, predicted from PICRUSt, is mainly attributed to deterministic processes in all microbial communities. The sink and source microbial communities are normally assembled using similar mechanisms, and the core microorganisms are specific to different environment types. On a global scale, deterministic processes are positively related to the community alpha diversity, microbial interaction degree and bacterial predatory-specific gene abundance. Our analysis provides a panoramic picture and regularities of global and environment-typical microbial community assemblies. IMPORTANCE With the development of sequencing technologies, the research topic of microbial ecology has evolved from the analysis of community composition to community assembly, including the relative contribution of deterministic and stochastic processes for the formation and maintenance of community diversity. Many studies have reported the microbial assembly mechanisms in various habitats, but the assembly regularities of global microbial communities remain unknown. In this study, we analyzed the EMP data set using a combined pipeline to explore the assembly mechanisms of global microbial communities, microbial sources to construct communities, core microbes in different environment types, and community-internal factors influencing assembly. The results provide a panoramic picture and rules of global and environment-typical microbial community assemblies, which enhances our understandings of the mechanisms globally controlling community diversity and species coexistence.

RevDate: 2023-04-24
CmpDate: 2023-04-18

Hou T, Dai H, Wang Q, et al (2023)

Dissecting the causal effect between gut microbiota, DHA, and urate metabolism: A large-scale bidirectional Mendelian randomization.

Frontiers in immunology, 14:1148591.

OBJECTIVES: Our aim was to investigate the interactive causal effects between gut microbiota and host urate metabolism and explore the underlying mechanism using genetic methods.

METHODS: We extracted summary statistics from the abundance of 211 microbiota taxa from the MiBioGen (N =18,340), 205 microbiota metabolism pathways from the Dutch Microbiome Project (N =7738), gout from the Global Biobank Meta-analysis Initiative (N =1,448,128), urate from CKDGen (N =288,649), and replication datasets from the Global Urate Genetics Consortium (N gout =69,374; N urate =110,347). We used linkage disequilibrium score regression and bidirectional Mendelian randomization (MR) to detect genetic causality between microbiota and gout/urate. Mediation MR and colocalization were performed to investigate potential mediators in the association between microbiota and urate metabolism.

RESULTS: Two taxa had a common causal effect on both gout and urate, whereas the Victivallaceae family was replicable. Six taxa were commonly affected by both gout and urate, whereas the Ruminococcus gnavus group genus was replicable. Genetic correlation supported significant results in MR. Two microbiota metabolic pathways were commonly affected by gout and urate. Mediation analysis indicated that the Bifidobacteriales order and Bifidobacteriaceae family had protective effects on urate mediated by increasing docosahexaenoic acid. These two bacteria shared a common causal variant rs182549 with both docosahexaenoic acid and urate, which was located within MCM6/LCT locus.

CONCLUSIONS: Gut microbiota and host urate metabolism had a bidirectional causal association, implicating the critical role of host-microbiota crosstalk in hyperuricemic patients. Changes in gut microbiota can not only ameliorate host urate metabolism but also become a foreboding indicator of urate metabolic diseases.

RevDate: 2023-07-01

Dilmore AH, Martino C, Neth BJ, et al (2023)

Effects of a ketogenic and low-fat diet on the human metabolome, microbiome, and foodome in adults at risk for Alzheimer's disease.

Alzheimer's & dementia : the journal of the Alzheimer's Association [Epub ahead of print].

INTRODUCTION: The ketogenic diet (KD) is an intriguing therapeutic candidate for Alzheimer's disease (AD) given its protective effects against metabolic dysregulation and seizures. Gut microbiota are essential for KD-mediated neuroprotection against seizures as well as modulation of bile acids, which play a major role in cholesterol metabolism. These relationships motivated our analysis of gut microbiota and metabolites related to cognitive status following a controlled KD intervention compared with a low-fat-diet intervention.

METHODS: Prediabetic adults, either with mild cognitive impairment (MCI) or cognitively normal (CN), were placed on either a low-fat American Heart Association diet or high-fat modified Mediterranean KD (MMKD) for 6 weeks; then, after a 6-week washout period, they crossed over to the alternate diet. We collected stool samples for shotgun metagenomics and untargeted metabolomics at five time points to investigate individuals' microbiome and metabolome throughout the dietary interventions.

RESULTS: Participants with MCI on the MMKD had lower levels of GABA-producing microbes Alistipes sp. CAG:514 and GABA, and higher levels of GABA-regulating microbes Akkermansia muciniphila. MCI individuals with curcumin in their diet had lower levels of bile salt hydrolase-containing microbes and an altered bile acid pool, suggesting reduced gut motility.

DISCUSSION: Our results suggest that the MMKD may benefit adults with MCI through modulation of GABA levels and gut-transit time.

RevDate: 2023-04-13
CmpDate: 2023-03-29

Zhang Y, Wang Y, Tang M, et al (2023)

The microbial dark matter and "wanted list" in worldwide wastewater treatment plants.

Microbiome, 11(1):59.

BACKGROUND: Wastewater treatment plants (WWTPs) are one of the largest biotechnology applications in the world and are of critical importance to modern urban societies. An accurate evaluation of the microbial dark matter (MDM, microorganisms whose genomes remain uncharacterized) proportions in WWTPs is of great value, while there is no such research yet. This study conducted a global meta-analysis of MDM in WWTPs with 317,542 prokaryotic genomes from the Genome Taxonomy Database and proposed a "wanted list" for priority targets in further investigations of activated sludge.

RESULTS: Compared with the Earth Microbiome Project data, WWTPs had relatively lower genome-sequenced proportions of prokaryotes than other ecosystems, such as the animal related environments. Analysis showed that the median proportions of the genome-sequenced cells and taxa (100% identity and 100% coverage in 16S rRNA gene region) in WWTPs reached 56.3% and 34.5% for activated sludge, 48.6% and 28.5% for aerobic biofilm, and 48.3% and 28.5% for anaerobic digestion sludge, respectively. This result meant MDM had high proportions in WWTPs. Besides, all of the samples were occupied by a few predominant taxa, and the majority of the sequenced genomes were from pure cultures. The global-scale "wanted list" for activated sludge contained four phyla that have few representatives and 71 operational taxonomic units with the majority of them having no genome or isolate yet. Finally, several genome mining methods were verified to successfully recover genomes from activated sludge such as hybrid assembly of the second- and third-generation sequencing.

CONCLUSIONS: This work elucidated the proportion of MDM in WWTPs, defined the "wanted list" of activated sludge for future investigations, and certified potential genome recovery methods. The proposed methodology of this study can be applied to other ecosystems and improve understanding of ecosystem structure across diverse habitats. Video Abstract.

RevDate: 2023-04-07
CmpDate: 2023-03-28

Zhao Y, Yi J, Xiang J, et al (2023)

Exploration of lung mycobiome in the patients with non-small-cell lung cancer.

BMC microbiology, 23(1):81.

As the Human Microbiome Project (HMP) progresses, the relationship between microbes and human health has been receiving increasing attention. A growing number of reports support the correlation between cancer and microbes. However, most studies have focused on bacteria, rather than fungal communities. In this study, we studied the alteration in lung mycobiome in patients with non-small-cell lung cancer (NSCLC) using metagenomic sequencing and qPCR. The higher fungal diversity and more complex network were observed in the patients with NSCLC. In addition, Alternaria arborescens was found as the most relevant fungus to NSCLC, and the enrichment of it in cancerous tissue was also detected. This study proposes that the changes in fungal communities may be closely related to lung cancer, and provides insights into further exploration the relationship between lung cancer and fungi.

RevDate: 2023-04-15

Zhou C, Wang Y, Li C, et al (2023)

Amelioration of Colitis by a Gut Bacterial Consortium Producing Anti-Inflammatory Secondary Bile Acids.

Microbiology spectrum, 11(2):e0333022 [Epub ahead of print].

The Integrative Human Microbiome Project and other cohort studies have indicated that inflammatory bowel disease is accompanied by dysbiosis of gut microbiota, decreased production of secondary bile acids, and increased levels of primary bile acids. Secondary bile acids, such as ursodeoxycholic acid (UDCA) and lithocholic acid (LCA), have been reported to be anti-inflammatory, yet it remains to be studied whether introducing selected bacteria strains to restore bile acid metabolism of the gut microbiome can alleviate intestinal inflammation. In this study, we screened human gut bacterial strains for bile acid metabolism and designed a consortium of three species, including Clostridium AP sp000509125, Bacteroides ovatus, and Eubacterium limosum, and named it BAC (bile acid consortium). We showed that the three-strain gut bacterial consortium BAC is capable of converting conjugated primary bile acids taurochenodeoxycholic acid and glycochenodeoxycholic acid to secondary bile acids UDCA and LCA in vitro. Oral gavage treatment with BAC in mice resulted in protective effects against dextran sulfate sodium (DSS)-induced colitis, including reduced weight loss and increased colon length. Furthermore, BAC treatment increased the fecal level of bile acids, including UDCA and LCA. BAC treatment enhanced intestinal barrier function, which may be attributed to the increased activation of the bile acid receptor TGR5 by secondary bile acids. Finally, we examined the remodeling of gut microbiota by BAC treatment. Taken together, the three-strain gut bacterial consortium BAC restored the dysregulated bile acid metabolism and alleviated DSS-induced colitis. Our study provides a proof-of-concept demonstration that a rationally designed bacterial consortium can reshape the metabolism of the gut microbiome to treat diseases. IMPORTANCE Secondary bile acids have been reported to be anti-inflammatory, yet it remains to be studied whether introducing selected bacteria strains to restore bile acid metabolism of the gut microbiome can alleviate intestinal inflammation. To address this gap, we designed a consortium of human gut bacterial strains based on their metabolic capacity to produce secondary bile acids UDCA and LCA, and we evaluated the efficacy of single bacterial strains and the bacterial consortium in treating the murine colitis model. We found that oral gavage of the bacterial consortium to mice restored secondary bile acid metabolism to increase levels of UDCA and LCA, which induced the activation of TGR5 to improve gut-barrier integrity and reduced the inflammation in murine colitis. Overall, our study demonstrates that rationally designed bacterial consortia can reshape the metabolism of the gut microbiome and provides novel insights into the application of live biotherapeutics for treating IBD.

RevDate: 2023-03-30
CmpDate: 2023-03-30

Zou H, Sun T, Jin B, et al (2023)

sBGC-hm: an atlas of secondary metabolite biosynthetic gene clusters from the human gut microbiome.

Bioinformatics (Oxford, England), 39(3):.

SUMMARY: Microbial secondary metabolites exhibit potential medicinal value. A large number of secondary metabolite biosynthetic gene clusters (BGCs) in the human gut microbiome, which exhibit essential biological activity in microbe-microbe and microbe-host interactions, have not been adequately characterized, making it difficult to prioritize these BGCs for experimental characterization. Here, we present the sBGC-hm, an atlas of secondary metabolite BGCs allows researchers to explore the potential therapeutic benefits of these natural products. One of its key features is the ability to assist in optimizing the BGC structure by utilizing the gene co-occurrence matrix obtained from Human Microbiome Project data. Results are viewable online and can be downloaded as spreadsheets.

The database is openly available at https://www.wzubio.com/sbgc. The website is powered by Apache 2 server with PHP and MariaDB.

RevDate: 2023-04-16
CmpDate: 2023-04-04

Seymour CO, Palmer M, Becraft ED, et al (2023)

Hyperactive nanobacteria with host-dependent traits pervade Omnitrophota.

Nature microbiology, 8(4):727-744.

Candidate bacterial phylum Omnitrophota has not been isolated and is poorly understood. We analysed 72 newly sequenced and 349 existing Omnitrophota genomes representing 6 classes and 276 species, along with Earth Microbiome Project data to evaluate habitat, metabolic traits and lifestyles. We applied fluorescence-activated cell sorting and differential size filtration, and showed that most Omnitrophota are ultra-small (~0.2 μm) cells that are found in water, sediments and soils. Omnitrophota genomes in 6 classes are reduced, but maintain major biosynthetic and energy conservation pathways, including acetogenesis (with or without the Wood-Ljungdahl pathway) and diverse respirations. At least 64% of Omnitrophota genomes encode gene clusters typical of bacterial symbionts, suggesting host-associated lifestyles. We repurposed quantitative stable-isotope probing data from soils dominated by andesite, basalt or granite weathering and identified 3 families with high isotope uptake consistent with obligate bacterial predators. We propose that most Omnitrophota inhabit various ecosystems as predators or parasites.

RevDate: 2023-03-14

Zhao J, Rodriguez J, W Martens-Habbena (2023)

Fine-scale evaluation of two standard 16S rRNA gene amplicon primer pairs for analysis of total prokaryotes and archaeal nitrifiers in differently managed soils.

Frontiers in microbiology, 14:1140487.

The advance of high-throughput molecular biology tools allows in-depth profiling of microbial communities in soils, which possess a high diversity of prokaryotic microorganisms. Amplicon-based sequencing of 16S rRNA genes is the most common approach to studying the richness and composition of soil prokaryotes. To reliably detect different taxonomic lineages of microorganisms in a single soil sample, an adequate pipeline including DNA isolation, primer selection, PCR amplification, library preparation, DNA sequencing, and bioinformatic post-processing is required. Besides DNA sequencing quality and depth, the selection of PCR primers and PCR amplification reactions arguably have the largest influence on the results. This study tested the performance and potential bias of two primer pairs, i.e., 515F (Parada)-806R (Apprill) and 515F (Parada)-926R (Quince) in the standard pipelines of 16S rRNA gene Illumina amplicon sequencing protocol developed by the Earth Microbiome Project (EMP), against shotgun metagenome-based 16S rRNA gene reads. The evaluation was conducted using five differently managed soils. We observed a higher richness of soil total prokaryotes by using reverse primer 806R compared to 926R, contradicting to in silico evaluation results. Both primer pairs revealed various degrees of taxon-specific bias compared to metagenome-derived 16S rRNA gene reads. Nonetheless, we found consistent patterns of microbial community variation associated with different land uses, irrespective of primers used. Total microbial communities, as well as ammonia oxidizing archaea (AOA), the predominant ammonia oxidizers in these soils, shifted along with increased soil pH due to agricultural management. In the unmanaged low pH plot abundance of AOA was dominated by the acid-tolerant NS-Gamma clade, whereas limed agricultural plots were dominated by neutral-alkaliphilic NS-Delta/NS-Alpha clades. This study stresses how primer selection influences community composition and highlights the importance of primer selection for comparative and integrative studies, and that conclusions must be drawn with caution if data from different sequencing pipelines are to be compared.

RevDate: 2023-03-01

Morrison AG, Sarkar S, Umar S, et al (2023)

The Contribution of the Human Oral Microbiome to Oral Disease: A Review.

Microorganisms, 11(2):.

The oral microbiome is an emerging field that has been a topic of discussion since the development of next generation sequencing and the implementation of the human microbiome project. This article reviews the current literature surrounding the oral microbiome, briefly highlighting most recent methods of microbiome characterization including cutting edge omics, databases for the microbiome, and areas with current gaps in knowledge. This article also describes reports on microorganisms contained in the oral microbiome which include viruses, archaea, fungi, and bacteria, and provides an in-depth analysis of their significant roles in tissue homeostasis. Finally, we detail key bacteria involved in oral disease, including oral cancer, and the current research surrounding their role in stimulation of inflammatory cytokines, the role of gingival crevicular fluid in periodontal disease, the creation of a network of interactions between microorganisms, the influence of the planktonic microbiome and cospecies biofilms, and the implications of antibiotic resistance. This paper provides a comprehensive literature analysis while also identifying gaps in knowledge to enable future studies to be conducted.

RevDate: 2023-02-14
CmpDate: 2023-02-14

Zhang MN, Xie R, Wang HG, et al (2023)

Cepharanthine Alleviates DSS-Induced Ulcerative Colitis via Regulating Aconitate Decarboxylase 1 Expression and Macrophage Infiltration.

Molecules (Basel, Switzerland), 28(3):.

Cepharanthine (CEP), a bisbenzylisoquinoline alkaloid from tubers of Stephania, protects against some inflammatory diseases. Aconitate decarboxylase 1 (ACOD1) is also known as immune-responsive gene 1 (IRG1), which plays an important immunometabolism role in inflammatory diseases by mediating the production of itaconic acid. ACOD1 exhibits abnormal expression in ulcerative colitis (UC). However, whether CEP can combat UC by affecting ACOD1 expression remains unanswered. This study was designed to explore the protective effects and mechanisms of CEP in treating colitis through in vitro and in vivo experiments. In vitro assays indicated that CEP inhibited LPS-induced secretion of pro-inflammatory cytokines and ACOD1 expression in RAW264.7 macrophages. Additionally, in the mouse model of DSS-induced colitis, CEP decreased macrophage infiltration and ACOD1 expression in colon tissue. After treatment with antibiotics (Abx), the expression of ACOD1 changed with the composition of gut microbiota. Correlation analysis also revealed that Family-XIII-AD3011-group and Rumini-clostridium-6 were positively correlated with ACOD1 expression level. Additionally, data of the integrative Human Microbiome Project (iHMP) showed that ACOD1 was highly expressed in the colon tissue of UC patients and this expression was positively correlated with the severity of intestinal inflammation. Collectively, CEP can counter UC by modulating gut microbiota and inhibiting the expression of ACOD1. CEP may serve as a potential pharmaceutical candidate in the treatment of UC.

RevDate: 2023-02-01
CmpDate: 2023-01-24

Kustrimovic N, Bombelli R, Baci D, et al (2023)

Microbiome and Prostate Cancer: A Novel Target for Prevention and Treatment.

International journal of molecular sciences, 24(2):.

Growing evidence of the microbiome's role in human health and disease has emerged since the creation of the Human Microbiome Project. Recent studies suggest that alterations in microbiota composition (dysbiosis) may play an essential role in the occurrence, development, and prognosis of prostate cancer (PCa), which remains the second most frequent male malignancy worldwide. Current advances in biological technologies, such as high-throughput sequencing, transcriptomics, and metabolomics, have enabled research on the gut, urinary, and intra-prostate microbiome signature and the correlation with local and systemic inflammation, host immunity response, and PCa progression. Several microbial species and their metabolites facilitate PCa insurgence through genotoxin-mediated mutagenesis or by driving tumor-promoting inflammation and dysfunctional immunosurveillance. However, the impact of the microbiome on PCa development, progression, and response to treatment is complex and needs to be fully understood. This review addresses the current knowledge on the host-microbe interaction and the risk of PCa, providing novel insights into the intraprostatic, gut, and urinary microbiome mechanisms leading to PCa carcinogenesis and treatment response. In this paper, we provide a detailed overview of diet changes, gut microbiome, and emerging therapeutic approaches related to the microbiome and PCa. Further investigation on the prostate-related microbiome and large-scale clinical trials testing the efficacy of microbiota modulation approaches may improve patient outcomes while fulfilling the literature gap of microbial-immune-cancer-cell mechanistic interactions.

RevDate: 2023-03-29
CmpDate: 2023-03-28

Sun H, Wang P, Y Li (2023)

An integrated microbiome project for charactering microbial diversity in classroom based on virtual simulation experiments.

Biochemistry and molecular biology education : a bimonthly publication of the International Union of Biochemistry and Molecular Biology, 51(2):171-179.

Microbiome study requires both molecular techniques and bioinformatics skills, which are challenging for biologists to participate in this growing field. To introduce microbiome concepts and skills to students, a 6-week wet-lab and bioinformatics course for undergraduates was implemented through the project-based learning (PBL) approach. In the saliva microbiome project, students collected their saliva samples, performed DNA extraction and PCR amplification, followed by metagenomic analysis to compare the diversity and abundances of microbes among samples. First, students are required to practice molecular techniques and bioinformatics analysis skills in a virtual simulation lab. To our knowledge, our study is the first one to incorporate a virtual lab into microbiome experience. Then, students applied their recently acquired skills to produce and analyze their own 16S amplicon sequencing data and reported their results via a scientific report. The student learning outcomes show that the Virtual lab can improve students' laboratory techniques and research capabilities. Moreover, a simple pipeline to analyze 16S rRNA gene amplicon sequencing data is introduced in a step-by-step manner that helps students to develop analysis skills. This project can be modified as either a virtual course or a module within another course such as microbiology, molecular biology, and bioinformatics. Our study provides evidence on the positive impact of virtual labs on learning outcomes in undergraduate science education.

RevDate: 2023-03-13
CmpDate: 2023-01-10

Eggers S, Bixby M, Renzetti S, et al (2022)

Human Microbiome Mixture Analysis Using Weighted Quantile Sum Regression.

International journal of environmental research and public health, 20(1):.

Studies of the health effects of the microbiome often measure overall associations by using diversity metrics, and individual taxa associations in separate analyses, but do not consider the correlated relationships between taxa in the microbiome. In this study, we applied random subset weighted quantile sum regression with repeated holdouts (WQSRSRH), a mixture method successfully applied to 'omic data to account for relationships between many predictors, to processed amplicon sequencing data from the Human Microbiome Project. We simulated a binary variable associated with 20 operational taxonomic units (OTUs). WQSRSRH was used to test for the association between the microbiome and the simulated variable, adjusted for sex, and sensitivity and specificity were calculated. The WQSRSRH method was also compared to other standard methods for microbiome analysis. The method was further illustrated using real data from the Growth and Obesity Cohort in Chile to assess the association between the gut microbiome and body mass index. In the analysis with simulated data, WQSRSRH predicted the correct directionality of association between the microbiome and the simulated variable, with an average sensitivity and specificity of 75% and 70%, respectively, in identifying the 20 associated OTUs. WQSRSRH performed better than all other comparison methods. In the illustration analysis of the gut microbiome and obesity, the WQSRSRH analysis identified an inverse association between body mass index and the gut microbe mixture, identifying Bacteroides, Clostridium, Prevotella, and Ruminococcus as important genera in the negative association. The application of WQSRSRH to the microbiome allows for analysis of the mixture effect of all the taxa in the microbiome, while simultaneously identifying the most important to the mixture, and allowing for covariate adjustment. It outperformed other methods when using simulated data, and in analysis with real data found results consistent with other study findings.

RevDate: 2023-01-10
CmpDate: 2022-12-27

Dang T, Kumaishi K, Usui E, et al (2022)

Stochastic variational variable selection for high-dimensional microbiome data.

Microbiome, 10(1):236.

BACKGROUND: The rapid and accurate identification of a minimal-size core set of representative microbial species plays an important role in the clustering of microbial community data and interpretation of clustering results. However, the huge dimensionality of microbial metagenomics datasets is a major challenge for the existing methods such as Dirichlet multinomial mixture (DMM) models. In the approach of the existing methods, the computational burden of identifying a small number of representative species from a large number of observed species remains a challenge.

RESULTS: We propose a novel approach to improve the performance of the widely used DMM approach by combining three ideas: (i) we propose an indicator variable to identify representative operational taxonomic units that substantially contribute to the differentiation among clusters; (ii) to address the computational burden of high-dimensional microbiome data, we propose a stochastic variational inference, which approximates the posterior distribution using a controllable distribution called variational distribution, and stochastic optimization algorithms for fast computation; and (iii) we extend the finite DMM model to an infinite case by considering Dirichlet process mixtures and estimating the number of clusters as a variational parameter. Using the proposed method, stochastic variational variable selection (SVVS), we analyzed the root microbiome data collected in our soybean field experiment, the human gut microbiome data from three published datasets of large-scale case-control studies and the healthy human microbiome data from the Human Microbiome Project.

CONCLUSIONS: SVVS demonstrates a better performance and significantly faster computation than those of the existing methods in all cases of testing datasets. In particular, SVVS is the only method that can analyze massive high-dimensional microbial data with more than 50,000 microbial species and 1000 samples. Furthermore, a core set of representative microbial species is identified using SVVS that can improve the interpretability of Bayesian mixture models for a wide range of microbiome studies. Video Abstract.

RevDate: 2023-07-31
CmpDate: 2023-07-31

Mishra K, Isali I, Sindhani M, et al (2023)

Characterization of Changes in Penile Microbiome Following Pediatric Circumcision.

European urology focus, 9(4):669-680.

BACKGROUND: While microbiome and host regulation contribute independently to many disease states, it is unclear how circumcision in pediatric population influences subsequent changes in penile microbiome.

OBJECTIVE: Our study aims to analyze jointly paired taxonomic profiles and assess pathways implicated in inflammation, barrier protection, and energy metabolism.

We analyzed 11 paired samples, periurethral collection, before and after circumcision, to generate microbiome and mycobiome profiling. Sample preparation of 16S ribosomal RNA and internal transcribed spacer sequencing was adapted from the methods developed by the National Institutes of Health Human Microbiome Project.

We obtained the predictive functional attributes of the microbial communities between samples using Silva-Tax4Fun and the Greengenes-Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) approach. The predictive functioning of the microbial communities was determined by linearly combining the normalized taxonomic abundances into the precomputed association matrix of Kyoto Encyclopedia of Genes and Genomes orthology reference profiles.

RESULTS AND LIMITATIONS: Several notable microbiome and mycobiome compositional differences were observed between pre- and postcircumcision patients. Pairwise comparisons across taxa revealed a significant decrease (p < 0.05, false discovery rate corrected) of microbiome organisms (Clostridiales, Bacteroidales, and Campylobacterales) and mycobiome (Saccharomycetales and Pleosporales) following circumcision. A total of 14 pathways were found to differ in abundance between the pre- and postcircumcision groups (p < 0.005, false discovery rate <0.1 and linear discriminant analysis score >3; five enriched and nine depleted). The pathways reduced after circumcision were mostly involved with amino acid and glucose metabolism, while pathways prior to circumcision were enriched in genetic information processing and transcription processes. As expected, enrichment in methyl-accepting chemotaxis protein, an integral membrane protein involved in directed motility of microbes to chemical cues and environment, occurred prior to circumcision, while the filamentous hemagglutinin pathway (a strong immunogenic protein) was depleted after circumcision CONCLUSIONS: Our results offer greater insight into the host-microbiota relationship of penile circumcision and may serve to lay the groundwork for future studies focused on drivers of inflammation, infection, and oncogenesis.

PATIENT SUMMARY: Our study showed a significant reduction in bacteria and fungi after circumcision, particularly anaerobic bacteria, which are known to be potential inducers of inflammation and cancer. This is the first study of its kind showing the changes in microbiome after circumcision, and some of the changes that occur in healthy infants after circumcision that may explain the differences in cancer and inflammatory disorders in adulthood.

RevDate: 2022-12-26

Bruno A, Fumagalli S, Ghisleni G, et al (2022)

The Microbiome of the Built Environment: The Nexus for Urban Regeneration for the Cities of Tomorrow.

Microorganisms, 10(12):.

Built environments are, for most of us, our natural habitat. In the last 50 years, the built-up area has more than doubled, with a massive biodiversity loss. The undeniable benefits of a city providing all the basic needs to a growing population showed longer-term and less obvious costs to human health: autoimmune and non-communicable diseases, as well as antimicrobial resistance, have reached unprecedented and alarming levels. Humans coevolved with microbes, and this long-lasting alliance is affected by the loss of connection with natural environments, misuse of antibiotics, and highly sanitized environments. Our aim is to direct the focus onto the microbial communities harbored by the built environments we live in. They represent the nexus for urban regeneration, which starts from a healthy environment. Planning a city means considering, in a two-fold way, the ecosystem health and the multidimensional aspects of wellbeing, including social, cultural, and aesthetic values. The significance of this perspective is inspiring guidelines and strategies for the urban regeneration of the cities of tomorrow, exploiting the invaluable role of microbial biodiversity and the ecosystem services that it could provide to create the robust scientific knowledge that is necessary for a bioinformed design of buildings and cities for healthy and sustainable living.

RevDate: 2023-03-20
CmpDate: 2022-12-21

Jesus HNR, Ramos JN, Rocha DJPG, et al (2022)

The pan-genome of the emerging multidrug-resistant pathogen Corynebacterium striatum.

Functional & integrative genomics, 23(1):5.

Corynebacterium striatum, a common constituent of the human skin microbiome, is now considered an emerging multidrug-resistant pathogen of immunocompromised and chronically ill patients. However, little is known about the molecular mechanisms in the transition from colonization to the multidrug-resistant (MDR) invasive phenotype in clinical isolates. This study performed a comprehensive pan-genomic analysis of C. striatum, including isolates from "normal skin microbiome" and from MDR infections, to gain insights into genetic factors contributing to pathogenicity and multidrug resistance in this species. For this, three novel genome sequences were obtained from clinical isolates of C. striatum of patients from Brazil, and other 24 complete or draft C. striatum genomes were retrieved from GenBank, including the ATCC6940 isolate from the Human Microbiome Project. Analysis of C. striatum strains demonstrated the presence of an open pan-genome (α = 0.852803) containing 3816 gene families, including 15 antimicrobial resistance (AMR) genes and 32 putative virulence factors. The core and accessory genomes included 1297 and 1307 genes, respectively. The identified AMR genes are primarily associated with resistance to aminoglycosides and tetracyclines. Of these, 66.6% are present in genomic islands, and four AMR genes, including aac(6')-ib7, are located in a class 1-integron. In conclusion, our data indicated that C. striatum possesses genomic characteristics favorable to the invasive phenotype, with high genomic plasticity, a robust genetic arsenal for iron acquisition, and important virulence determinants and AMR genes present in mobile genetic elements.

RevDate: 2023-01-04
CmpDate: 2022-12-27

Zhang W, Han N, Zhang T, et al (2022)

The Spatial Features and Temporal Changes in the Gut Microbiota of a Healthy Chinese Population.

Microbiology spectrum, 10(6):e0131022.

In this study, we aimed to understand the characteristics of the gut microbial composition in a healthy Chinese population and to evaluate if they differed across different regions. In addition, we aimed to understand the changes in the gut microbial composition over time. We collected 239 fecal samples from healthy Chinese adults living in four regions and performed a 1-year time cohort study in a small population in Beijing. The Chinese gut microbiota share 34 core bacterial genera and 39 core bacterial species, which exist in all collected samples. Several disease-related microorganisms (DRMs), virulence factors, and antibiotic resistance genes were found in one or more healthy Chinese samples. Differences in gut microbiota were observed in samples from different regions, locations, individuals, and time points. Compared to other factors, time was associated with a lower degree of change in the gut microbiota. Our findings revealed spatial and temporal changes in the gut microbiota of healthy Chinese individuals. Compared to fecal microbiomes of 152 samples in the publicly released the Human Microbiome Project (HMP) project from the United States, samples in this study have higher variability in the fecal microbiome, with higher richness, Shannon diversity indices, and Pielou evenness indexes, at both the genus and species levels. The microbiota data obtained in this study will provide a detailed basis for further understanding the composition of the gut microbiota in the healthy Chinese population. IMPORTANCE China accounts for approximately 1/5th of the world's total population. Differences in environment, ethnicity, and living habits could impart unique features to the structure of the gut microbiota of Chinese individuals. In 2016, we started to investigate healthy Chinese people and their gut microbiomes. Phase I results for 16S rRNA amplicons have been released. However, owing to the limitations of 16S rRNA amplicon sequencing, the gut microbiome of a healthy Chinese population could not be examined thoroughly at the species level, and the detailed changes in the gut microbiota over time need to be investigated. To address these knowledge gaps, we started a phase II study and investigated the basis for variations in the gut microbiome composition in a healthy Chinese population at the species level using shotgun metagenomics technology. In the phase II study, we also conducted a time scale analysis of fecal samples from healthy Chinese subjects, as a pioneered study, which quantitatively clarified the changes in the gut microbiota at both the spatial and temporal levels and elucidated the distribution pattern of DRMs in healthy Chinese individuals.

RevDate: 2023-03-22
CmpDate: 2023-02-13

Li DD, Zhang Z, Wang JN, et al (2023)

Estimate of the degradation potentials of cellulose, xylan, and chitin across global prokaryotic communities.

Environmental microbiology, 25(2):397-409.

Complex polysaccharides (e.g. cellulose, xylan, and chitin), the most abundant renewable biomass resources available on Earth, are mainly degraded by microorganisms in nature. However, little is known about the global distribution of the enzymes and microorganisms responsible for the degradation of cellulose, xylan, and chitin in natural environments. Through large-scale alignments between the sequences released by the Earth Microbiome Project and sequenced prokaryotic genomes, we determined that almost all prokaryotic communities have the functional potentials to degrade cellulose, xylan, and chitin. The median abundances of genes encoding putative cellulases, xylanases, and chitinases in global prokaryotic communities are 0.51 (0.17-1.01), 0.24 (0.05-0.57), and 0.33 (0.11-0.71) genes/cell, respectively, and the composition and abundance of these enzyme systems are environmentally varied. The taxonomic sources of the three enzymes are highly diverse within prokaryotic communities, and the main factor influencing the diversity is the community's alpha diversity index rather than gene abundance. Moreover, there are obvious differences in taxonomic sources among different communities, and most genera with degradation potentials are narrowly distributed. In conclusion, our analysis preliminarily depicts a panorama of cellulose-, xylan-, and chitin-degrading enzymatic systems across global prokaryotic communities.

RevDate: 2023-06-17
CmpDate: 2022-12-02

Shaffer JP, Nothias LF, Thompson LR, et al (2022)

Standardized multi-omics of Earth's microbiomes reveals microbial and metabolite diversity.

Nature microbiology, 7(12):2128-2150.

Despite advances in sequencing, lack of standardization makes comparisons across studies challenging and hampers insights into the structure and function of microbial communities across multiple habitats on a planetary scale. Here we present a multi-omics analysis of a diverse set of 880 microbial community samples collected for the Earth Microbiome Project. We include amplicon (16S, 18S, ITS) and shotgun metagenomic sequence data, and untargeted metabolomics data (liquid chromatography-tandem mass spectrometry and gas chromatography mass spectrometry). We used standardized protocols and analytical methods to characterize microbial communities, focusing on relationships and co-occurrences of microbially related metabolites and microbial taxa across environments, thus allowing us to explore diversity at extraordinary scale. In addition to a reference database for metagenomic and metabolomic data, we provide a framework for incorporating additional studies, enabling the expansion of existing knowledge in the form of an evolving community resource. We demonstrate the utility of this database by testing the hypothesis that every microbe and metabolite is everywhere but the environment selects. Our results show that metabolite diversity exhibits turnover and nestedness related to both microbial communities and the environment, whereas the relative abundances of microbially related metabolites vary and co-occur with specific microbial consortia in a habitat-specific manner. We additionally show the power of certain chemistry, in particular terpenoids, in distinguishing Earth's environments (for example, terrestrial plant surfaces and soils, freshwater and marine animal stool), as well as that of certain microbes including Conexibacter woesei (terrestrial soils), Haloquadratum walsbyi (marine deposits) and Pantoea dispersa (terrestrial plant detritus). This Resource provides insight into the taxa and metabolites within microbial communities from diverse habitats across Earth, informing both microbial and chemical ecology, and provides a foundation and methods for multi-omics microbiome studies of hosts and the environment.

RevDate: 2023-03-08

Ganz HH, Jospin G, Rojas CA, et al (2022)

The Kitty Microbiome Project: Defining the Healthy Fecal "Core Microbiome" in Pet Domestic Cats.

Veterinary sciences, 9(11):.

Here, we present a taxonomically defined fecal microbiome dataset for healthy domestic cats (Felis catus) fed a range of commercial diets. We used this healthy reference dataset to explore how age, diet, and living environment correlate with fecal microbiome composition. Thirty core bacterial genera were identified. Prevotella, Bacteroides, Collinsella, Blautia, and Megasphaera were the most abundant, and Bacteroides, Blautia, Lachnoclostridium, Sutterella, and Ruminococcus gnavus were the most prevalent. While community composition remained relatively stable across different age classes, the number of core taxa present decreased significantly with age. Fecal microbiome composition varied with host diet type. Cats fed kibble had a slightly, but significantly greater number of core taxa compared to cats not fed any kibble. The core microbiomes of cats fed some raw food contained taxa not as highly prevalent or abundant as cats fed diets that included kibble. Living environment also had a large effect on fecal microbiome composition. Cats living in homes differed significantly from those in shelters and had a greater portion of their microbiomes represented by core taxa. Collectively our work reinforces the findings that age, diet, and living environment are important factors to consider when defining a core microbiome in a population.

RevDate: 2022-12-23
CmpDate: 2022-12-22

Gupta VK, Bakshi U, Chang D, et al (2022)

TaxiBGC: a Taxonomy-Guided Approach for Profiling Experimentally Characterized Microbial Biosynthetic Gene Clusters and Secondary Metabolite Production Potential in Metagenomes.

mSystems, 7(6):e0092522.

Biosynthetic gene clusters (BGCs) in microbial genomes encode bioactive secondary metabolites (SMs), which can play important roles in microbe-microbe and host-microbe interactions. Given the biological significance of SMs and the current profound interest in the metabolic functions of microbiomes, the unbiased identification of BGCs from high-throughput metagenomic data could offer novel insights into the complex chemical ecology of microbial communities. Currently available tools for predicting BGCs from shotgun metagenomes have several limitations, including the need for computationally demanding read assembly, predicting a narrow breadth of BGC classes, and not providing the SM product. To overcome these limitations, we developed taxonomy-guided identification of biosynthetic gene clusters (TaxiBGC), a command-line tool for predicting experimentally characterized BGCs (and inferring their known SMs) in metagenomes by first pinpointing the microbial species likely to harbor them. We benchmarked TaxiBGC on various simulated metagenomes, showing that our taxonomy-guided approach could predict BGCs with much-improved performance (mean F1 score, 0.56; mean PPV score, 0.80) compared with directly identifying BGCs by mapping sequencing reads onto the BGC genes (mean F1 score, 0.49; mean PPV score, 0.41). Next, by applying TaxiBGC on 2,650 metagenomes from the Human Microbiome Project and various case-control gut microbiome studies, we were able to associate BGCs (and their SMs) with different human body sites and with multiple diseases, including Crohn's disease and liver cirrhosis. In all, TaxiBGC provides an in silico platform to predict experimentally characterized BGCs and their SM production potential in metagenomic data while demonstrating important advantages over existing techniques. IMPORTANCE Currently available bioinformatics tools to identify BGCs from metagenomic sequencing data are limited in their predictive capability or ease of use to even computationally oriented researchers. We present an automated computational pipeline called TaxiBGC, which predicts experimentally characterized BGCs (and infers their known SMs) in shotgun metagenomes by first considering the microbial species source. Through rigorous benchmarking techniques on simulated metagenomes, we show that TaxiBGC provides a significant advantage over existing methods. When demonstrating TaxiBGC on thousands of human microbiome samples, we associate BGCs encoding bacteriocins with different human body sites and diseases, thereby elucidating a possible novel role of this antibiotic class in maintaining the stability of microbial ecosystems throughout the human body. Furthermore, we report for the first time gut microbial BGC associations shared among multiple pathologies. Ultimately, we expect our tool to facilitate future investigations into the chemical ecology of microbial communities across diverse niches and pathologies.

RevDate: 2023-07-01
CmpDate: 2022-11-14

Liu Y, Elworth RAL, Jochum MD, et al (2022)

De novo identification of microbial contaminants in low microbial biomass microbiomes with Squeegee.

Nature communications, 13(1):6799.

Computational analysis of host-associated microbiomes has opened the door to numerous discoveries relevant to human health and disease. However, contaminant sequences in metagenomic samples can potentially impact the interpretation of findings reported in microbiome studies, especially in low-biomass environments. Contamination from DNA extraction kits or sampling lab environments leaves taxonomic "bread crumbs" across multiple distinct sample types. Here we describe Squeegee, a de novo contamination detection tool that is based upon this principle, allowing the detection of microbial contaminants when negative controls are unavailable. On the low-biomass samples, we compare Squeegee predictions to experimental negative control data and show that Squeegee accurately recovers putative contaminants. We analyze samples of varying biomass from the Human Microbiome Project and identify likely, previously unreported kit contamination. Collectively, our results highlight that Squeegee can identify microbial contaminants with high precision and thus represents a computational approach for contaminant detection when negative controls are unavailable.

RevDate: 2022-11-19
CmpDate: 2022-11-18

Rasmussen N (2022)

René Dubos, the Autochthonous Flora, and the Discovery of the Microbiome.

Journal of the history of biology, 55(3):537-558.

Now characterised by high-throughput sequencing methods that enable the study of microbes without lab culture, the human "microbiome" (the microbial flora of the body) is said to have revolutionary implications for biology and medicine. According to many experts, we must now understand ourselves as "holobionts" like lichen or coral, multispecies superorganisms that consist of animal and symbiotic microbes in combination, because normal physiological function depends on them. Here I explore the 1960s research of biologist René Dubos, a forerunner figure mentioned in some historical accounts of the microbiome, and argue that he arrived at the superorganism concept 40 years before the Human Microbiome Project. This raises the question of why his contribution was not hailed as revolutionary at the time and why Dubos is not remembered for it.

RevDate: 2022-11-02
CmpDate: 2022-10-28

Fransson E, Gudnadottir U, Hugerth LW, et al (2022)

Cohort profile: the Swedish Maternal Microbiome project (SweMaMi) - assessing the dynamic associations between the microbiome and maternal and neonatal adverse events.

BMJ open, 12(10):e065825.

PURPOSE: The Swedish Maternal Microbiome (SweMaMi) project was initiated to better understand the dynamics of the microbiome in pregnancy, with longitudinal microbiome sampling, shotgun metagenomics, extensive questionnaires and health registry linkage.

PARTICIPANTS: Pregnant women were recruited before the 20th gestational week during 2017-2021 in Sweden. In total, 5439 pregnancies (5193 unique women) were included. For 3973 pregnancies (73%), samples were provided at baseline, and for 3141 (58%) at all three timepoints (second and third trimester and postpartum). In total, 38 591 maternal microbiome samples (vaginal, faecal and saliva) and 3109 infant faecal samples were collected. Questionnaires were used to collect information on general, reproductive and mental health, diet and lifestyle, complemented by linkage to the nationwide health registries, also used to follow up the health of the offspring (up to age 10).

FINDINGS TO DATE: The cohort is fairly representative for the total Swedish pregnant population (data from 2019), with 41% first-time mothers. Women with university level education, born in Sweden, with normal body mass index, not using tobacco-products and aged 30-34 years were slightly over-represented.

FUTURE PLANS: The sample and data collection were finalised in November 2021. The next steps are the characterisation of the microbial DNA and linkage to the health and demographic information from the questionnaires and registries. The role of the microbiome on maternal and neonatal outcomes and early-childhood diseases will be explored (including preterm birth, miscarriage) and the role and interaction of other risk factors and confounders (including endometriosis, polycystic ovarian syndrome, diet, drug use). This is currently among the largest pregnancy cohorts in the world with longitudinal design and detailed and standardised microbiome sampling enabling follow-up of both mothers and children. The findings are expected to contribute greatly to the field of reproductive health focusing on pregnancy and neonatal outcomes.

RevDate: 2022-11-02
CmpDate: 2022-10-26

Gupta A, Singh V, I Mani (2022)

Dysbiosis of human microbiome and infectious diseases.

Progress in molecular biology and translational science, 192(1):33-51.

Since birth, the human body gets colonized by various communities of symbiotic or commensal microorganisms and they persist till the death of an individual. The human microbiome is comprised of the genomes of microorganisms such as viruses, archaea, eukaryotes, protozoa, and, most remarkably, bacteria. The development of "omics" technologies gave way to the Human Microbiome Project (HMP) which aimed at exploring the collection of microbial genes and genomes inhabiting the human body. Eubiosis, i.e., a healthy and balanced composition of such microbes contributes to the metabolic function, protection against pathogens and provides nutrients and energy to the host. Whereas, an imbalance in the diversity of microorganisms, termed dysbiosis, greatly influences the state of health and disease. This chapter summarizes the impact of gut bacteria on the well-being of humans and highlights the protective role played by the human microbiota during bacterial and viral infections. The condition of dysbiosis and how it plays a role in the establishment of various infections and metabolic disorders such as Clostridioides difficile infection (CFI), inflammatory bowel disease (IBD), cancer, periodontitis, and obesity are described in detail. Further, treatments such as fecal transplantation, probiotics, prebiotics, phage therapy, and CRISPR/Cas system, which target gut microbiota during digestive diseases are also discussed.

RevDate: 2022-10-25

Zheng Y, Shi J, Chen Q, et al (2022)

Identifying individual-specific microbial DNA fingerprints from skin microbiomes.

Frontiers in microbiology, 13:960043.

Skin is an important ecosystem that links the human body and the external environment. Previous studies have shown that the skin microbial community could remain stable, even after long-term exposure to the external environment. In this study, we explore two questions: Do there exist strains or genetic variants in skin microorganisms that are individual-specific, temporally stable, and body site-independent? And if so, whether such microorganismal genetic variants could be used as markers, called "fingerprints" in our study, to identify donors? We proposed a framework to capture individual-specific DNA microbial fingerprints from skin metagenomic sequencing data. The fingerprints are identified on the frequency of 31-mers free from reference genomes and sequence alignments. The 616 metagenomic samples from 17 skin sites at 3-time points from 12 healthy individuals from Integrative Human Microbiome Project were adopted. Ultimately, one contig for each individual is assembled as a fingerprint. And results showed that 89.78% of the skin samples despite body sites could identify their donors correctly. It is observed that 10 out of 12 individual-specific fingerprints could be aligned to Cutibacterium acnes. Our study proves that the identified fingerprints are temporally stable, body site-independent, and individual-specific, and can identify their donors with enough accuracy. The source code of the genetic identification framework is freely available at https://github.com/Ying-Lab/skin_fingerprint.

RevDate: 2022-12-22
CmpDate: 2022-10-24

Khorsand B, Asadzadeh Aghdaei H, Nazemalhosseini-Mojarad E, et al (2022)

Overrepresentation of Enterobacteriaceae and Escherichia coli is the major gut microbiome signature in Crohn's disease and ulcerative colitis; a comprehensive metagenomic analysis of IBDMDB datasets.

Frontiers in cellular and infection microbiology, 12:1015890.

OBJECTIVES: A number of converging strands of research suggest that the intestinal Enterobacteriaceae plays a crucial role in the development and progression of inflammatory bowel disease (IBD), however, the changes in the abundance of Enterobacteriaceae species and their related metabolic pathways in Crohn's disease (CD) and ulcerative colitis (UC) compared to healthy people are not fully explained by comprehensive comparative metagenomics analysis. In the current study, we investigated the alternations of the Enterobacterales population in the gut microbiome of patients with CD and UC compared to healthy subjects.

METHODS: Metagenomic datasets were selected from the Integrative Human Microbiome Project (HMP2) through the Inflammatory Bowel Disease Multi'omics Database (IBDMDB). We performed metagenome-wide association studies on fecal samples from 191 CD patients, 132 UC patients, and 125 healthy controls (HCs). We used the metagenomics dataset to study bacterial community structure, relative abundance, differentially abundant bacteria, functional analysis, and Enterobacteriaceae-related biosynthetic pathways.

RESULTS: Compared to the gut microbiome of HCs, six Enterobacteriaceae species were significantly elevated in both CD and UC patients, including Escherichia coli, Klebsiella variicola, Klebsiella quasipneumoniae, Klebsiella pneumoniae, Proteus mirabilis, Citrobacter freundii, and Citrobacter youngae, while Klebsiella oxytoca, Morganella morganii, and Citrobacter amalonaticus were uniquely differentially abundant and enriched in the CD cohort. Four species were uniquely differentially abundant and enriched in the UC cohort, including Citrobacter portucalensis, Citrobacter pasteurii, Citrobacter werkmanii, and Proteus hauseri. Our analysis also showed a dramatically increased abundance of E. coli in their intestinal bacterial community. Biosynthetic pathways of aerobactin siderophore, LPS, enterobacterial common antigen, nitrogen metabolism, and sulfur relay systems encoded by E. coli were significantly elevated in the CD samples compared to the HCs. Menaquinol biosynthetic pathways were associated with UC that belonged to K. pneumoniae strains.

CONCLUSIONS: In conclusion, compared with healthy people, the taxonomic and functional composition of intestinal bacteria in CD and UC patients was significantly shifted to Enterobacteriaceae species, mainly E. coli and Klebsiella species.

RevDate: 2022-12-07
CmpDate: 2022-10-20

Vikramdeo KS, Anand S, Pierce JY, et al (2022)

Distribution of microbiota in cervical preneoplasia of racially disparate populations.

BMC cancer, 22(1):1074.

BACKGROUNDS: Microbiome dysbiosis is an important contributing factor in tumor development and thus may be a risk predictor for human malignancies. In the United States, women with Hispanic/Latina (HIS) and African American (AA) background have a higher incidence of cervical cancer and poorer outcomes than Caucasian American (CA) women.

METHODS: Here, we assessed the distribution pattern of microbiota in cervical intraepithelial neoplasia (CIN) lesions obtained from HIS (n = 12), AA (n = 12), and CA (n = 12) women, who were screened for CC risk assessment. We employed a 16S rRNA gene sequencing approach adapted from the NIH-Human Microbiome Project to identify the microbial niche in all CIN lesions (n = 36).

RESULTS: We detected an appreciably decreased abundance of beneficial Lactobacillus in the CIN lesions of the AA and HIS women compared to the CA women. Differential abundance of potentially pathogenic Prevotella, Delftia, Gardnerella, and Fastidiosipila was also evident among the various racial groups. An increased abundance of Micrococcus was also evident in AA and HIS women compared to the CA women. The detection level of Rhizobium was higher among the AA ad CA women compared to the HIS women. In addition to the top 10 microbes, a unique niche of 27 microbes was identified exclusively in women with a histopathological diagnosis of CIN. Among these microbes, a group of 8 microbiota; Rubellimicrobium, Podobacter, Brevibacterium, Paracoccus, Atopobium, Brevundimonous, Comamonous, and Novospingobium was detected only in the CIN lesions obtained from AA and CA women.

CONCLUSIONS: Microbial dysbiosis in the cervical epithelium represented by an increased ratio of potentially pathogenic to beneficial microbes may be associated with increased CC risk disparities. Developing a race-specific reliable panel of microbial markers could be beneficial for CC risk assessment, disease prevention, and/or therapeutic guidance.

RevDate: 2023-03-08
CmpDate: 2022-10-17

Rinaldi F, Pinto D, Borsani E, et al (2022)

The First Evidence of Bacterial Foci in the Hair Part and Dermal Papilla of Scalp Hair Follicles: A Pilot Comparative Study in Alopecia Areata.

International journal of molecular sciences, 23(19):.

The role of the microbiome in hair follicle (HF) growth represents a growing field of research. Here, we studied the bacterial population in the scalp hair follicles of subjects with alopecia areata (AA). Two Healthy and two AA subjects, respectively (20−60 years old), were enrolled and studied regarding the microbial community in the subepidermal scalp compartments by means of a 4-mm biopsy punch. Samples were examined by 16S sequencing, histochemical staining (Gram’s method), and transmission electron microscopy (TEM). Bacterial foci were observed in the AA subjects’ follicles with both the two adopted complementary approaches (electron microscopy and Gram staining). Significant (p < 0.05) differences were also found in the three-layer biopsy samples (p < 0.05) regarding the bacterial population. In particular, in the deep epidermis and dermis levels, a significant (p < 0.05) lower abundance of Firmicutes and a higher abundance of Proteobacteria were found in AA samples compared to the healthy control. Firmicutes also showed a significant (p < 0.05) lower abundance in hypodermis in AA subjects. In addition, Enterobacteriaceae and the genera Streptococcus, Gemella, Porphyromonas, and Granulicatella were relatively more abundant in AA groups at the deep epidermis level. The Staphylococcus and Flavobacterium genera were significantly less abundant in AA samples than in controls in all three-layer biopsy samples (p < 0.05). In contrast, Veillonella and Neisseriaceae were relatively more abundant in the healthy control group compared to the AA sample. Therefore, higher alpha diversity was observed in all three-layer biopsy samples of AA patients compared to the control. In conclusion, our data suggest that tAA could be defined as a “hair disease associated with dysregulated microbiome-immunity axis of hair follicles”.

RevDate: 2022-11-30
CmpDate: 2022-10-17

Prakash A, Nourianpour M, Senok A, et al (2022)

Polycystic Ovary Syndrome and Endometrial Cancer: A Scoping Review of the Literature on Gut Microbiota.

Cells, 11(19):.

Gut dysbiosis has been associated with polycystic ovary syndrome (PCOS) and endometrial cancer (EC) but no studies have investigated whether gut dysbiosis may explain the increased endometrial cancer risk in polycystic ovary syndrome. The aim of this scoping review is to evaluate the extent and nature of published studies on the gut microbiota in polycystic ovary syndrome and endometrial cancer and attempt to find any similarities between the composition of the microbiota. We searched for publications ranging from the years 2016 to 2022, due to the completion date of the 'Human Microbiome Project' in 2016. We obtained 200 articles by inputting keywords such as 'gut microbiome', 'gut microbiota', 'gut dysbiosis', 'PCOS', and 'endometrial cancer' into search engines such as PubMed and Scopus. Of the 200 identified in our initial search, we included 25 articles in our final review after applying the exclusion and inclusion criteria. Although the literature is growing in this field, we did not identify enough published studies to investigate whether gut dysbiosis may explain the increased EC risk in PCOS. Within the studies identified, we were unable to identify any consistent patterns of the microbiome similarly present in studies on women with PCOS compared with women with EC. Although we found that the phylum Firmicutes was similarly decreased in women with PCOS and studies on women with EC, there was however significant variability within the studies identified making it highly likely that this may have arisen by chance. Further research pertaining to molecular and microbiological mechanisms in relation to the gut microbiome is needed to elucidate a greater understanding of its contribution to the pathophysiology of endometrial cancer in patients with polycystic ovarian syndrome.

RevDate: 2022-09-28

Aboul Naga SH, Hassan LM, El Zanaty RT, et al (2022)

Behçet uveitis: Current practice and future perspectives.

Frontiers in medicine, 9:968345.

Described as early as Hippocrates in his "Third Book of Endemic Diseases," Behçet's Disease (BD), also known as "The Silk Road Disease" following its initial demographics, consists of a triad of recurrent oro-genital ulcers and associated uveitis. Current demographics and rising percentages of patients seen far beyond the Silk Road in Ocular Inflammatory Disease and Uveitis Clinics list BD uveitis as one of the frontliners of non-infectious autoinflammatory eye diseases. Clinical features of BD and juvenile-onset BD are detailed alongside various approaches in classification and suggested algorithms for diagnosis that are outlined in this review. With the ongoing Human Microbiome Project and studies such as the MAMBA study, the role of the human microbiome in BD is highlighted in the pathophysiology of BD to include the current research and literature perspective. Furthermore, with the advancement of recent diagnostic and investigative techniques, especially in the field of Optical Coherence Tomography (OCT), disease-related characteristics are updated to encompass SD, EDI and OCT-angiography characteristics of BD. Having entered the era of biologic therapy, the role of various specific cytokine-blocking biologic drugs, such as TNF-α inhibitors (e.g., adalimumab, infliximab), interferon α-2a inhibitors, IL-6 and IL-1 inhibitors are presented and contrasted alongside the conventional immunosuppressant drugs and the classic old gold standard: corticosteroids (systemic or local). Finally, with the ongoing SARS-CoV-2 pandemic, it was not possible to conclude the review without reviewing the latest evidence-based literature reporting BD morbidity in this era, the observed pattern and treatment recommendations as well as those related to reported post-vaccine complications and emergence of BD.

RevDate: 2023-01-11
CmpDate: 2022-11-23

de Lima Ferreira JK, de Mello Varani A, Tótola MR, et al (2022)

Phylogenomic characterization and pangenomic insights into the surfactin-producing bacteria Bacillus subtilis strain RI4914.

Brazilian journal of microbiology : [publication of the Brazilian Society for Microbiology], 53(4):2051-2063.

Bacillus subtilis is a versatile bacterial species able to produce surfactin, a lipopeptide biosurfactant. We carried out the phylogenomic characterization and pangenomic analyses using available B. subtilis complete genomes. Also, we report the whole genome of the biosurfactant-producing B. subtilis strain RI4914 that was isolated from effluent water from an oil exploration field. We applied a hybrid sequencing approach using both long- and short-read sequencing technologies to generate a highly accurate, single-chromosome genome. The pangenomics analysis of 153 complete genomes classified as B. subtilis retrieved from the NCBI shows an open pangenome composed of 28,511 accessory genes, which agrees with the high genetic plasticity of the species. Also, this analysis suggests that surfactin production is a common trait shared by members of this species since the srfA operon is highly conserved among the B. subtilis strains found in most of the assemblies available. Finally, increased surfactin production corroborates the higher srfAA gene expression in B. subtilis strain RI4914.

RevDate: 2023-01-06
CmpDate: 2022-12-23

An U, Shenhav L, Olson CA, et al (2022)

STENSL: Microbial Source Tracking with ENvironment SeLection.

mSystems, 7(5):e0099521.

Microbial source tracking analysis has emerged as a widespread technique for characterizing the properties of complex microbial communities. However, this analysis is currently limited to source environments sampled in a specific study. In order to expand the scope beyond one single study and allow the exploration of source environments using large databases and repositories, such as the Earth Microbiome Project, a source selection procedure is required. Such a procedure will allow differentiating between contributing environments and nuisance ones when the number of potential sources considered is high. Here, we introduce STENSL (microbial Source Tracking with ENvironment SeLection), a machine learning method that extends common microbial source tracking analysis by performing an unsupervised source selection and enabling sparse identification of latent source environments. By incorporating sparsity into the estimation of potential source environments, STENSL improves the accuracy of true source contribution, while significantly reducing the noise introduced by noncontributing ones. We therefore anticipate that source selection will augment microbial source tracking analyses, enabling exploration of multiple source environments from publicly available repositories while maintaining high accuracy of the statistical inference. IMPORTANCE Microbial source tracking is a powerful tool to characterize the properties of complex microbial communities. However, this analysis is currently limited to source environments sampled in a specific study. In many applications there is a clear need to consider source selection over a large array of microbial environments, external to the study. To this end, we developed STENSL (microbial Source Tracking with ENvironment SeLection), an expectation-maximization algorithm with sparsity that enables the identification of contributing sources among a large set of potential microbial environments. With the unprecedented expansion of microbiome data repositories such as the Earth Microbiome Project, recording over 200,000 samples from more than 50 types of categorized environments, STENSL takes the first steps in performing automated source exploration and selection. STENSL is significantly more accurate in identifying the contributing sources as well as the unknown source, even when considering hundreds of potential source environments, settings in which state-of-the-art microbial source tracking methods add considerable error.

RevDate: 2022-09-10
CmpDate: 2022-08-23

Wiesmann C, Lehr K, Kupcinskas J, et al (2022)

Primers matter: Influence of the primer selection on human fungal detection using high throughput sequencing.

Gut microbes, 14(1):2110638.

Microbiota research has received an increasing attention for its role in disease development and fungi are considered as one of the key players in the microbial niche. Various sequencing approaches have been applied to uncover the role of fungal community in health and disease; however, little is known on the performance of various primers and comparability between the studies. Motivated by the recent publications, we performed a systematic comparison of the 18S and ITS regions to identify the impact of various primers on the sequencing results. Using four pairs of primers extensively used in literature, fungal community was retrieve from 25 fecal samples, and applying high throughput sequencing; and the results were compared in order to select the most suitable primers for fungal detection in human fecal samples. Considering the high variability between samples, primers described in the Earth microbiome project detected the broadest fungal spectrum suggesting its superior performance in mycobiome research.

RevDate: 2022-09-26
CmpDate: 2022-09-08

Scricciolo A, Lombardo V, Elli L, et al (2022)

Use of a proline-specific endopeptidase to reintroduce gluten in patients with non-coeliac gluten sensitivity: A randomized trial.

Clinical nutrition (Edinburgh, Scotland), 41(9):2025-2030.

BACKGROUND: A gluten-free diet (GFD) is the main therapy for non-coeliac gluten sensitivity (NCGS). However, the availability of novel enzymes with the ability to digest gluten could represent a therapeutic opportunity for NCGS patients to avoid a GFD.

AIMS: To evaluate the controlled reintroduction of gluten with or without the endopeptidase P1016 in NCGS patients.

METHODS: This is a randomized, double-blind, placebo-controlled monocentric study, Registered under ClinicalTrials.gov Identifier no. NCT01864993. Gluten was reintroduced incrementally over a 3-week period under nutritional control. NCGS patients were randomized into two groups and administered P1016 or placebo during gluten reintroduction. We evaluated symptoms (visual analogue scale, VAS), quality of life (SF-36) and mental health symptoms (SCL-90) on a weekly basis.

RESULTS: We enrolled a total 23 patients who were allocated to a placebo group (n = 11, age 38.4 ± 2.9) or an intervention group (n = 12, age 39.5 ± 3.1). No effect of P1016 on symptoms was found. During gluten reintroduction, patients reported a significant increase in abdominal pain and a worsening of stool consistency. Furthermore, no differences were found between the groups regarding SCL-90 and SF-36 scores.

CONCLUSIONS: Our results demonstrate a lack of effect of P1016 in the management of NCGS patients and the possible reintroduction of gluten.

RevDate: 2022-08-16

Wei Q, Li Z, Gu Z, et al (2022)

Shotgun metagenomic sequencing reveals skin microbial variability from different facial sites.

Frontiers in microbiology, 13:933189.

Biogeography (body site) is known to be one of the main factors influencing the composition of the skin microbial community. However, site-associated microbial variability at a fine-scale level was not well-characterized since there was a lack of high-resolution recognition of facial microbiota across kingdoms by shotgun metagenomic sequencing. To investigate the explicit microbial variance in the human face, 822 shotgun metagenomic sequencing data from Han Chinese recently published by our group, in combination with 97 North American samples from NIH Human Microbiome Project (HMP), were reassessed. Metagenomic profiling of bacteria, fungi, and bacteriophages, as well as enriched function modules from three facial sites (forehead, cheek, and the back of the nose), was analyzed. The results revealed that skin microbial features were more alike in the forehead and cheek while varied from the back of the nose in terms of taxonomy and functionality. Analysis based on biogeographic theories suggested that neutral drift with niche selection from the host could possibly give rise to the variations. Of note, the abundance of porphyrin-producing species, i.e., Cutibacterium acnes, Cutibacterium avidum, Cutibacterium granulosum, and Cutibacterium namnetense, was all the highest in the back of the nose compared with the forehead/cheek, which was consistent with the highest porphyrin level on the nose in our population. Sequentially, the site-associated microbiome variance was confirmed in American populations; however, it was not entirely consistent. Furthermore, our data revealed correlation patterns between Propionibacterium acnes bacteriophages with genus Cutibacterium at different facial sites in both populations; however, C. acnes exhibited a distinct correlation with P. acnes bacteriophages in Americans/Chinese. Taken together, in this study, we explored the fine-scale facial site-associated changes in the skin microbiome and provided insight into the ecological processes underlying facial microbial variations.

RevDate: 2022-12-22
CmpDate: 2022-12-22

Zheng X, Dai X, Zhu Y, et al (2022)

(Meta)Genomic Analysis Reveals Diverse Energy Conservation Strategies Employed by Globally Distributed Gemmatimonadota.

mSystems, 7(4):e0022822.

Gemmatimonadota is a phylum-level lineage distributed widely but rarely reported. Only six representatives of Gemmatimonadota have so far been isolated and cultured in laboratory. The physiology, ecology, and evolutionary history of this phylum remain unknown. The 16S rRNA gene survey of our salt lake and deep-sea sediments, and Earth Microbiome Project (EMP) samples, reveals that Gemmatimonadota exist in diverse environments globally. In this study, we retrieved 17 metagenome-assembled genomes (MAGs) from salt lake sediments (12 MAGs) and deep-sea sediments (5 MAGs). Analysis of these MAGs and the nonredundant MAGs or genomes from public databases reveals Gemmatimonadota can degrade various complex organic substrates, and mainly employ heterotrophic pathways (e.g., glycolysis and tricarboxylic acid [TCA] cycle) for growth via aerobic respiration. And the processes of sufficient energy being stored in glucose through gluconeogenesis, followed by the synthesis of more complex compounds, are prevalent in Gemmatimonadota. A highly expandable pangenome for Gemmatimonadota has been observed, which presumably results from their adaptation to thriving in diverse environments. The enrichment of the Na[+]/H[+] antiporter in the SG8-23 order represents their adaptation to salty habitats. Notably, we identified a novel lineage of the SG8-23 order, which is potentially anoxygenic phototrophic. This lineage is not closely related to the phototrophs in the order of Gemmatimonadales. The two orders differ distinctly in the gene organization and phylogenetic relationship of their photosynthesis gene clusters, indicating photosystems in Gemmatimonadota have evolved in two independent routes. IMPORTANCE The phylum Gemmatimonadota is widely distributed in various environments. However, their physiology, ecology and evolutionary history remain unknown, primary due to the limited cultured isolates and available genomes. We were intrigued to find out how widespread this phylum is, and how it can thrive under diverse conditions. Our results here expand the knowledge of the genetic and metabolic diversity of Gemmatimonadota, and shed light on the diverse energy conservation strategies (i.e., oxidative phosphorylation, substrate phosphorylation, and photosynthetic phosphorylation) responsible for their global distribution. Moreover, gene organization and phylogenetic analysis of photosynthesis gene clusters in Gemmatimonadota provide a valuable insight into the evolutionary history of photosynthesis.

RevDate: 2022-09-14

Lopera-Maya EA, Kurilshikov A, van der Graaf A, et al (2022)

Author Correction: Effect of host genetics on the gut microbiome in 7,738 participants of the Dutch Microbiome Project.

Nature genetics, 54(9):1448.

RevDate: 2023-03-08
CmpDate: 2022-07-27

Silva SG, Paula P, da Silva JP, et al (2022)

Insights into the Antimicrobial Activities and Metabolomes of Aquimarina (Flavobacteriaceae, Bacteroidetes) Species from the Rare Marine Biosphere.

Marine drugs, 20(7):.

Two novel natural products, the polyketide cuniculene and the peptide antibiotic aquimarin, were recently discovered from the marine bacterial genus Aquimarina. However, the diversity of the secondary metabolite biosynthetic gene clusters (SM-BGCs) in Aquimarina genomes indicates a far greater biosynthetic potential. In this study, nine representative Aquimarina strains were tested for antimicrobial activity against diverse human-pathogenic and marine microorganisms and subjected to metabolomic and genomic profiling. We found an inhibitory activity of most Aquimarina strains against Candida glabrata and marine Vibrio and Alphaproteobacteria species. Aquimarina sp. Aq135 and Aquimarina muelleri crude extracts showed particularly promising antimicrobial activities, amongst others against methicillin-resistant Staphylococcus aureus. The metabolomic and functional genomic profiles of Aquimarina spp. followed similar patterns and were shaped by phylogeny. SM-BGC and metabolomics networks suggest the presence of novel polyketides and peptides, including cyclic depsipeptide-related compounds. Moreover, exploration of the ‘Sponge Microbiome Project’ dataset revealed that Aquimarina spp. possess low-abundance distributions worldwide across multiple marine biotopes. Our study emphasizes the relevance of this member of the microbial rare biosphere as a promising source of novel natural products. We predict that future metabologenomics studies of Aquimarina species will expand the spectrum of known secondary metabolites and bioactivities from marine ecosystems.

RevDate: 2022-07-21

Therdtatha P, Shinoda A, J Nakayama (2022)

Crisis of the Asian gut: associations among diet, microbiota, and metabolic diseases.

Bioscience of microbiota, food and health, 41(3):83-93.

The increase of lifestyle-related diseases in Asia has recently become remarkably serious. This has been associated with a change in dietary habits that may alter the complex gut microbiota and its metabolic function in Asian people. Notably, the penetration of modern Western diets into Asia, which has been accompanied by an increase in fat content and decrease in plant-derived dietary fiber, is restructuring the Asian gut microbiome. In this review, we introduce the current status of obesity and diabetes in Asia and discuss the links of changes in dietary style with gut microbiota alterations which may predispose Asian people to metabolic diseases.

RevDate: 2022-07-22
CmpDate: 2022-07-21

Pinto D, Calabrese FM, De Angelis M, et al (2022)

Lichen Planopilaris: The first biopsy layer microbiota inspection.

PloS one, 17(7):e0269933.

Lichen Planopilaris (LPP) is a lymphatic disease affecting the scalp that is characterized by a chronic and destructive inflammation process, named as 'cicatricial alopecia' in which the hair follicles are targeted and may involve predominantly lymphocytes or neutrophils. Scalp and biopsy layers have never been used to investigate microbial community composition and its relative taxa abundances in LPP. We sought to examine the significant taxa of this chronic relapsing inflammatory skin disease, together with inspect the existing connections with metabolic pathways featuring this microbial community. We used a multilevel analysis based on 16S rRNA marker sequencing in order to detect OTU abundances in pathologic/healthy samples, real time PCR for measuring the levels of IL-23 interleukin expression and urinary metabolomics to find out volatile organic metabolites (VOMs). By using a linear regression model, we described peculiar taxa that significantly differentiated LPP and healthy samples. We inspected taxa abundances and interleukin mRNA levels and the Microbacteriaceae family resulted negatively correlated with the IL-23 expression. Moreover, starting from 16S taxa abundances, we predicted the metabolic pathways featuring this microbial community. By inspecting microbial composition, sample richness, metabolomics profiles and the relative metabolic pathways in a cohort of LPP and healthy samples we deepened the contribution of significant taxa that are connected to inflammation maintenance and microbiota plasticity in LPP pathology.

RevDate: 2022-12-07

Balaji A, Sapoval N, Seto C, et al (2022)

KOMB: K-core based de novo characterization of copy number variation in microbiomes.

Computational and structural biotechnology journal, 20:3208-3222.

Characterizing metagenomes via kmer-based, database-dependent taxonomic classification has yielded key insights into underlying microbiome dynamics. However, novel approaches are needed to track community dynamics and genomic flux within metagenomes, particularly in response to perturbations. We describe KOMB, a novel method for tracking genome level dynamics within microbiomes. KOMB utilizes K-core decomposition to identify Structural variations (SVs), specifically, population-level Copy Number Variation (CNV) within microbiomes. K-core decomposition partitions the graph into shells containing nodes of induced degree at least K, yielding reduced computational complexity compared to prior approaches. Through validation on a synthetic community, we show that KOMB recovers and profiles repetitive genomic regions in the sample. KOMB is shown to identify functionally-important regions in Human Microbiome Project datasets, and was used to analyze longitudinal data and identify keystone taxa in Fecal Microbiota Transplantation (FMT) samples. In summary, KOMB represents a novel graph-based, taxonomy-oblivious, and reference-free approach for tracking CNV within microbiomes. KOMB is open source and available for download at https://gitlab.com/treangenlab/komb.

RevDate: 2023-03-02
CmpDate: 2023-01-23

Reis DJ, Kaizer AM, Kinney AR, et al (2023)

The unique association of posttraumatic stress disorder with hypertension among veterans: A replication of Kibler et al. (2009) using Bayesian estimation and data from the United States-Veteran Microbiome Project.

Psychological trauma : theory, research, practice and policy, 15(1):131-139.

OBJECTIVE: Kibler et al. (2009) reported that hypertension was related to PTSD independent of depression. These two conditions have significant diagnostic overlap. The present study sought to conceptually replicate this work with a veteran sample, using Bayesian estimation to directly update past results, as well as examine symptom severity scores in relation to hypertension.

METHOD: This was a secondary analysis of data obtained from the United States-Veteran Microbiome Project. Lifetime diagnoses of PTSD and major depressive disorder (MDD) were obtained from a structured clinical interview and hypertension diagnoses were extracted from electronic medical records. PTSD and depressive symptom severity were obtained from self-report measures. Logistic regressions with Bayesian estimation were used to estimate the associations between hypertension and (a) psychiatric diagnostic history and (b) symptom severity scores.

RESULTS: Compared with veterans without lifetime diagnoses of either disorder, the PTSD-only group was estimated to have a 29% increase in hypertension risk, and the PTSD + MDD group was estimated to have a 66% increase in hypertension risk. Additionally, higher levels of PTSD symptom severity were associated with a higher risk of hypertension.

CONCLUSION: PTSD diagnosis and symptom severity are uniquely associated with hypertension, independent of MDD or depressive symptom severity. These results support previous findings that PTSD might be a modifiable risk factor for the prevention and treatment of hypertension. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

RevDate: 2023-01-07
CmpDate: 2022-09-26

Nagata N, Nishijima S, Miyoshi-Akiyama T, et al (2022)

Population-level Metagenomics Uncovers Distinct Effects of Multiple Medications on the Human Gut Microbiome.

Gastroenterology, 163(4):1038-1052.

BACKGROUND & AIMS: Medication is a major determinant of human gut microbiome structure, and its overuse increases the risks of morbidity and mortality. However, effects of certain commonly prescribed drugs and multiple medications on the gut microbiome are still underinvestigated.

METHODS: We performed shotgun metagenomic analysis of fecal samples from 4198 individuals in the Japanese 4D (Disease, Drug, Diet, Daily life) microbiome project. A total of 759 drugs were profiled, and other metadata, such as anthropometrics, lifestyles, diets, physical activities, and diseases, were prospectively collected. Second fecal samples were collected from 243 individuals to assess the effects of drug initiation and discontinuation on the microbiome.

RESULTS: We found that numerous drugs across different treatment categories influence the microbiome; more than 70% of the drugs we profiled had not been examined before. Individuals exposed to multiple drugs, polypharmacy, showed distinct gut microbiome structures harboring significantly more abundant upper gastrointestinal species and several nosocomial pathobionts due to additive drug effects. Polypharmacy was also associated with microbial functions, including the reduction of short-chain fatty acid metabolism and increased bacterial stress responses. Even nonantibiotic drugs were significantly correlated with an increased antimicrobial resistance potential through polypharmacy. Notably, a 2-time points dataset revealed the alteration and recovery of the microbiome in response to drug initiation and cessation, corroborating the observed drug-microbe associations in the cross-sectional cohort.

CONCLUSION: Our large-scale metagenomics unravels extensive and disruptive impacts of individual and multiple drug exposures on the human gut microbiome, providing a drug-microbe catalog as a basis for a deeper understanding of the role of the microbiome in drug efficacy and toxicity.

RevDate: 2022-07-16

Wang J, Feng J, Zhu Y, et al (2022)

Diversity and Biogeography of Human Oral Saliva Microbial Communities Revealed by the Earth Microbiome Project.

Frontiers in microbiology, 13:931065.

The oral cavity is an important window for microbial communication between the environment and the human body. The oral microbiome plays an important role in human health. However, compared to the gut microbiome, the oral microbiome has been poorly explored. Here, we analyzed 404 datasets from human oral saliva samples published by the Earth Microbiome Project (EMP) and compared them with 815 samples from the human gut, nose/pharynx, and skin. The diversity of the human saliva microbiome varied significantly among individuals, and the community compositions were complex and diverse. The saliva microbiome showed the lowest species diversity among the four environment types. Human oral habitats shared a small core bacterial community containing only 14 operational taxonomic units (OTUs) under 5 phyla, which occupied over 75% of the sequence abundance. For the four habitats, the core taxa of the saliva microbiome had the greatest impact on saliva habitats than other habitats and were mostly unique. In addition, the saliva microbiome showed significant differences in the populations of different regions, which may be determined by the living environment and lifestyle/dietary habits. Finally, the correlation analysis showed high similarity between the saliva microbiome and the microbiomes of Aerosol (non-saline) and Surface (non-saline), i.e., two environment types closely related to human, suggesting that contact and shared environment being the driving factors of microbial transmission. Together, these findings expand our understanding of human oral diversity and biogeography.

RevDate: 2023-04-17
CmpDate: 2022-11-14

Metwally AA, Zhang T, Wu S, et al (2022)

Robust identification of temporal biomarkers in longitudinal omics studies.

Bioinformatics (Oxford, England), 38(15):3802-3811.

MOTIVATION: Longitudinal studies increasingly collect rich 'omics' data sampled frequently over time and across large cohorts to capture dynamic health fluctuations and disease transitions. However, the generation of longitudinal omics data has preceded the development of analysis tools that can efficiently extract insights from such data. In particular, there is a need for statistical frameworks that can identify not only which omics features are differentially regulated between groups but also over what time intervals. Additionally, longitudinal omics data may have inconsistencies, including non-uniform sampling intervals, missing data points, subject dropout and differing numbers of samples per subject.

RESULTS: In this work, we developed OmicsLonDA, a statistical method that provides robust identification of time intervals of temporal omics biomarkers. OmicsLonDA is based on a semi-parametric approach, in which we use smoothing splines to model longitudinal data and infer significant time intervals of omics features based on an empirical distribution constructed through a permutation procedure. We benchmarked OmicsLonDA on five simulated datasets with diverse temporal patterns, and the method showed specificity greater than 0.99 and sensitivity greater than 0.87. Applying OmicsLonDA to the iPOP cohort revealed temporal patterns of genes, proteins, metabolites and microbes that are differentially regulated in male versus female subjects following a respiratory infection. In addition, we applied OmicsLonDA to a longitudinal multi-omics dataset of pregnant women with and without preeclampsia, and OmicsLonDA identified potential lipid markers that are temporally significantly different between the two groups.

We provide an open-source R package (https://bioconductor.org/packages/OmicsLonDA), to enable widespread use.

SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

RevDate: 2023-02-01

Darcy JL, Amend AS, Swift SOI, et al (2022)

specificity: an R package for analysis of feature specificity to environmental and higher dimensional variables, applied to microbiome species data.

Environmental microbiome, 17(1):34.

BACKGROUND: Understanding the factors that influence microbes' environmental distributions is important for determining drivers of microbial community composition. These include environmental variables like temperature and pH, and higher-dimensional variables like geographic distance and host species phylogeny. In microbial ecology, "specificity" is often described in the context of symbiotic or host parasitic interactions, but specificity can be more broadly used to describe the extent to which a species occupies a narrower range of an environmental variable than expected by chance. Using a standardization we describe here, Rao's (Theor Popul Biol, 1982. https://doi.org/10.1016/0040-5809(82)90004-1, Sankhya A, 2010. https://doi.org/10.1007/s13171-010-0016-3) Quadratic Entropy can be conveniently applied to calculate specificity of a feature, such as a species, to many different environmental variables.

RESULTS: We present our R package specificity for performing the above analyses, and apply it to four real-life microbial data sets to demonstrate its application. We found that many fungi within the leaves of native Hawaiian plants had strong specificity to rainfall and elevation, even though these variables showed minimal importance in a previous analysis of fungal beta-diversity. In Antarctic cryoconite holes, our tool revealed that many bacteria have specificity to co-occurring algal community composition. Similarly, in the human gut microbiome, many bacteria showed specificity to the composition of bile acids. Finally, our analysis of the Earth Microbiome Project data set showed that most bacteria show strong ontological specificity to sample type. Our software performed as expected on synthetic data as well.

CONCLUSIONS: specificity is well-suited to analysis of microbiome data, both in synthetic test cases, and across multiple environment types and experimental designs. The analysis and software we present here can reveal patterns in microbial taxa that may not be evident from a community-level perspective. These insights can also be visualized and interactively shared among researchers using specificity's companion package, specificity.shiny.

RevDate: 2022-07-16

García-Mato E, Martínez-Lamas L, Álvarez-Fernández M, et al (2022)

Molecular Detection of Streptococcus downii sp. nov. from Dental Plaque Samples from Patients with Down Syndrome and Non-Syndromic Individuals.

Microorganisms, 10(6):.

A new bacterial species has recently been identified in the dental plaque of an adolescent with Down syndrome. The species is known as Streptococcus downii sp. nov. (abbreviated to S. downii), and it inhibits the growth of S. mutans and certain periodontal pathogens. The aim of this study was to determine the distribution of S. downii in the oral cavity of individuals with Down syndrome. Methods: A specific polymerase chain reaction for the operon of bacteriocin (class IIb lactobin A/cerein 7B family) was designed to detect S. downii in individuals with Down syndrome (n = 200) and in the general population (n = 100). We also compared the whole genome of S. downii and the regions related to its bacteriocins against 127 metagenomes of supragingival plaque of the "Human Microbiome Project". Results: We detected the specific gene of the S. downii bacteriocin in an individual with Down syndrome (Cq, 34.52; GE/μL, 13.0) and in an individual of the non-syndromic control group (Cq, 34.78 Cq; GE/μL, 4.93). The prevalence of S. downii was ≤1% both in Down syndrome and in the general population, which did not allow for clinical-microbiological correlations to be established. This result was confirmed by detecting only one metagenome with an ANIm with approximately 95% homology and with 100% homology with ORFs that code class IIb lactobiocin A/cerein 7B bacteriocins among the 127 metagenomes of the "Human Microbiome Project" tested. Conclusions: The detection rate of S. downii in the supragingival dental plaque was very low, both in the Down syndrome individuals and in the non-syndromic controls. A clinical-microbiological correlation could therefore not be established.

RevDate: 2022-08-10
CmpDate: 2022-07-14

Shaffer JP, Carpenter CS, Martino C, et al (2022)

A comparison of six DNA extraction protocols for 16S, ITS and shotgun metagenomic sequencing of microbial communities.

BioTechniques, 73(1):34-46.

Microbial communities contain a broad phylogenetic diversity of organisms; however, the majority of methods center on describing bacteria and archaea. Fungi are important symbionts in many ecosystems and are potentially important members of the human microbiome, beyond those that can cause disease. To expand our analysis of microbial communities to include data from the fungal internal transcribed spacer (ITS) region, five candidate DNA extraction kits were compared against our standardized protocol for describing bacteria and archaea using 16S rRNA gene amplicon- and shotgun metagenomics sequencing. The results are presented considering a diverse panel of host-associated and environmental sample types and comparing the cost, processing time, well-to-well contamination, DNA yield, limit of detection and microbial community composition among protocols. Across all criteria, the MagMAX Microbiome kit was found to perform best. The PowerSoil Pro kit performed comparably but with increased cost per sample and overall processing time. The Zymo MagBead, NucleoMag Food and Norgen Stool kits were included.

RevDate: 2023-04-11
CmpDate: 2023-03-31

Kuhl LP, Marostica PJC, Macedo AJ, et al (2023)

High microbiome variability in pediatric tracheostomy cannulas in patients with similar clinical characteristics.

Brazilian journal of otorhinolaryngology, 89(2):254-263.

OBJECTIVES: To evaluate the bacterial microbiome found in tracheostomy cannulas of a group of children diagnosed with glossoptosis secondary to Robin Sequence (RS), and its clinical implications.

METHODS: Pediatric patients were enrolled in the study at the time of the cannula change in the hospital. During this procedure, the removed cannula was collected and stored for amplicon sequencing of 16s rRNA. DNA extraction was performed using DNeasy PowerBiofilm Kit (QIAGEN® ‒ Cat nº 24000-50) while sequencing was performed with the S5 (Ion S5™ System, Thermo Fisher Scientific), following Brazilian Microbiome Project (BMP) protocol.

RESULTS: All 12 patients included in the study were using tracheostomy uncuffed cannulas of the same brand, had tracheostomy performed for over 1-year and had used the removed cannula for approximately 3-months. Most abundant genera found were Aggregatibacter, Pseudomonas, Haemophilus, Neisseria, Staphylococcus, Fusobacterium, Moraxella, Streptococcus, Alloiococcus, and Capnocytophaga. Individual microbiome of each individual was highly variable, not correlating to any particular clinical characteristic.

CONCLUSION: The microbiome of tracheostomy cannulas is highly variable, even among patients with similar clinical characteristics, making it challenging to determine a standard for normality.

RevDate: 2022-07-16

Maestre-Carballa L, Navarro-López V, M Martinez-Garcia (2022)

A Resistome Roadmap: From the Human Body to Pristine Environments.

Frontiers in microbiology, 13:858831.

A comprehensive characterization of the human body resistome [sets of antibiotic resistance genes (ARGs)] is yet to be done and paramount for addressing the antibiotic microbial resistance threat. Here, we study the resistome of 771 samples from five major body parts (skin, nares, vagina, gut, and oral cavity) of healthy subjects from the Human Microbiome Project (HMP) and addressed the potential dispersion of ARGs in pristine environments. A total of 28,714 ARGs belonging to 235 different ARG types were found in the HMP proteome dataset (n = 9.1 × 10[7] proteins analyzed). Our study reveals a distinct resistome profile (ARG type and abundance) between body sites and high interindividual variability. Nares had the highest ARG load (≈5.4 genes/genome) followed by the oral cavity, whereas the gut showed one of the highest ARG richness (shared with nares) but the lowest abundance (≈1.3 genes/genome). The fluroquinolone resistance genes were the most abundant in the human body, followed by macrolide-lincosamide-streptogramin (MLS) or tetracycline. Most ARGs belonged to common bacterial commensals and multidrug resistance trait were predominant in the nares and vagina. Many ARGs detected here were considered as low risk for human health, whereas only a few of them, such as BlaZ, dfrA14, dfrA17, or tetM, were classified as high-risk ARG. Our data also provide hope, since the spread of common ARG from the human body to pristine environments (n = 271 samples; 77 Gb of sequencing data and 2.1 × 10[8] proteins analyzed) thus far remains very unlikely (only one case found in an autochthonous bacterium from a pristine environment). These findings broaden our understanding of ARG in the context of the human microbiome and the One-Health Initiative of WHO uniting human host-microbes and environments as a whole.

RevDate: 2022-07-16

Arjunan P, R Swaminathan (2022)

Do Oral Pathogens Inhabit the Eye and Play a Role in Ocular Diseases?.

Journal of clinical medicine, 11(10):.

Fascinatingly, the immune-privileged healthy eye has a small unique population of microbiota. The human microbiome project led to continuing interest in the ocular microbiome. Typically, ocular microflorae are commensals of low diversity that colonize the external and internal sites of the eye, without instigating any disorders. Ocular commensals modulate immunity and optimally regulate host defense against pathogenic invasion, both on the ocular surface and neuroretina. Yet, any alteration in this symbiotic relationship culminates in the perturbation of ocular homeostasis and shifts the equilibrium toward local or systemic inflammation and, in turn, impaired visual function. A compositional variation in the ocular microbiota is associated with surface disorders such as keratitis, blepharitis, and conjunctivitis. Nevertheless, innovative studies now implicate non-ocular microbial dysbiosis in glaucoma, age-related macular degeneration (AMD), uveitis, and diabetic retinopathy. Accordingly, prompt identification of the extra-ocular etiology and a methodical understanding of the mechanisms of invasion and host-microbial interaction is of paramount importance for preventative and therapeutic interventions for vision-threatening conditions. This review article aims to explore the current literature evidence to better comprehend the role of oral pathogens in the etiopathogenesis of ocular diseases, specifically AMD.

RevDate: 2022-08-14
CmpDate: 2022-05-23

Song SJ, Wang J, Martino C, et al (2021)

Naturalization of the microbiota developmental trajectory of Cesarean-born neonates after vaginal seeding.

Med (New York, N.Y.), 2(8):951-964.e5.

BACKGROUND: Early microbiota perturbations are associated with disorders that involve immunological underpinnings. Cesarean section (CS)-born babies show altered microbiota development in relation to babies born vaginally. Here we present the first statistically powered longitudinal study to determine the effect of restoring exposure to maternal vaginal fluids after CS birth.

METHODS: Using 16S rRNA gene sequencing, we followed the microbial trajectories of multiple body sites in 177 babies over the first year of life; 98 were born vaginally, and 79 were born by CS, of whom 30 were swabbed with a maternal vaginal gauze right after birth.

FINDINGS: Compositional tensor factorization analysis confirmed that microbiota trajectories of exposed CS-born babies aligned more closely with that of vaginally born babies. Interestingly, the majority of amplicon sequence variants from maternal vaginal microbiomes on the day of birth were shared with other maternal sites, in contrast to non-pregnant women from the Human Microbiome Project (HMP) study.

CONCLUSIONS: The results of this observational study prompt urgent randomized clinical trials to test whether microbial restoration reduces the increased disease risk associated with CS birth and the underlying mechanisms. It also provides evidence of the pluripotential nature of maternal vaginal fluids to provide pioneer bacterial colonizers for the newborn body sites. This is the first study showing long-term naturalization of the microbiota of CS-born infants by restoring microbial exposure at birth.

FUNDING: C&D, Emch Fund, CIFAR, Chilean CONICYT and SOCHIPE, Norwegian Institute of Public Health, Emerald Foundation, NIH, National Institute of Justice, Janssen.

RevDate: 2022-07-16
CmpDate: 2022-05-19

Sim M, Lee J, Wy S, et al (2022)

Generation and application of pseudo-long reads for metagenome assembly.

GigaScience, 11:.

BACKGROUND: Metagenomic assembly using high-throughput sequencing data is a powerful method to construct microbial genomes in environmental samples without cultivation. However, metagenomic assembly, especially when only short reads are available, is a complex and challenging task because mixed genomes of multiple microorganisms constitute the metagenome. Although long read sequencing technologies have been developed and have begun to be used for metagenomic assembly, many metagenomic studies have been performed based on short reads because the generation of long reads requires higher sequencing cost than short reads.

RESULTS: In this study, we present a new method called PLR-GEN. It creates pseudo-long reads from metagenomic short reads based on given reference genome sequences by considering small sequence variations existing in individual genomes of the same or different species. When applied to a mock community data set in the Human Microbiome Project, PLR-GEN dramatically extended short reads in length of 101 bp to pseudo-long reads with N50 of 33 Kbp and 0.4% error rate. The use of these pseudo-long reads generated by PLR-GEN resulted in an obvious improvement of metagenomic assembly in terms of the number of sequences, assembly contiguity, and prediction of species and genes.

CONCLUSIONS: PLR-GEN can be used to generate artificial long read sequences without spending extra sequencing cost, thus aiding various studies using metagenomes.

RevDate: 2023-05-10
CmpDate: 2023-05-10

Greene LK, McKenney EA, Gasper W, et al (2023)

Gut Site and Gut Morphology Predict Microbiome Structure and Function in Ecologically Diverse Lemurs.

Microbial ecology, 85(4):1608-1619.

Most studies of wildlife gut microbiotas understandably rely on feces to approximate consortia along the gastrointestinal tract. We therefore compared microbiome structure and predicted metagenomic function in stomach, small intestinal, cecal, and colonic samples from 52 lemurs harvested during routine necropsies. The lemurs represent seven genera (Cheirogaleus, Daubentonia, Varecia, Hapalemur, Eulemur, Lemur, Propithecus) characterized by diverse feeding ecologies and gut morphologies. In particular, the hosts variably depend on fibrous foodstuffs and show correlative morphological complexity in their large intestines. Across host lineages, microbiome diversity, variability, membership, and function differed between the upper and lower gut, reflecting regional tradeoffs in available nutrients. These patterns related minimally to total gut length but were modulated by fermentation capacity (i.e., the ratio of small to large intestinal length). Irrespective of feeding strategy, host genera with limited fermentation capacity harbored more homogenized microbiome diversity along the gut, whereas those with expanded fermentation capacity harbored cecal and colonic microbiomes with greater diversity and abundant fermentative Ruminococcaceae taxa. While highlighting the value of curated sample repositories for retrospective comparisons, our results confirm that the need to survive on fibrous foods, either routinely or in hypervariable environments, can shape the morphological and microbial features of the lower gut.

RevDate: 2022-08-10
CmpDate: 2022-07-01

Hu C, Beyda ND, KW Garey (2022)

A Vancomycin HPLC Assay for Use in Gut Microbiome Research.

Microbiology spectrum, 10(3):e0168821.

The human microbiome project has revolutionized our understanding of the interaction between commensal microbes and human health. By far, the biggest perturbation of the microbiome involves use of broad-spectrum antibiotics excreted in the gut. Thus, pharmacodynamics of microbiome changes in relation to drug exposure pharmacokinetics is an emerging field. However, reproducibility studies are necessary to develop the field. A simple and fast high-performance liquid chromatography-photodiode array detector (HPLC) method was validated for quantitative fecal vancomycin analysis. Reproducibility of results were tested based on sample storage time, homogeneity of antibiotic within stool, and concentration consistency after lyophilization. The HPLC method enabled the complete elution of vancomycin within ~4.2 min on the reversed-phase C18 column under the isocratic elution mode, with excellent recovery (85% to 110%) over a 4-log, quantitative range (0.4-100 μg/mL). Relative standard derivations (RSD) of intra-day and inter-day results ranged from 0.4% to 5.4%. Using sample stool aliquots of various weights consistently demonstrated similar vancomycin concentrations (mean RSD: 6%; range: 2-16%). After correcting for water concentrations, vancomycin concentrations obtained after lyophilization were similar to the concentrations obtained from the original samples (RSD less than 10%). These methodologies establish sample condition standards for a quantitative HPLC to enable vancomycin pharmacokinetic studies with the human microbiome. IMPORTANCE Research on antibiotic effect on the gut microbiome is an emerging field with standardization of research methods needed. In this study, a simple and fast high-performance liquid chromatography method was validated for quantitative fecal vancomycin analysis. Reproducibility of results were tested to standardize storage time, homogeneity of antibiotic within stool, and concentration consistency after lyophilization. These methodologies establish sample condition standards for a quantitative HPLC to enable vancomycin pharmacokinetic studies with the human microbiome.

RevDate: 2022-05-07

Gan R, Zhou F, Si Y, et al (2022)

DBSCAN-SWA: An Integrated Tool for Rapid Prophage Detection and Annotation.

Frontiers in genetics, 13:885048.

As an intracellular form of a bacteriophage in the bacterial host genome, a prophage usually integrates into bacterial DNA with high specificity and contributes to horizontal gene transfer (HGT). With the exponentially increasing number of microbial sequences uncovered in genomic or metagenomics studies, there is a massive demand for a tool that is capable of fast and accurate identification of prophages. Here, we introduce DBSCAN-SWA, a command line software tool developed to predict prophage regions in bacterial genomes. DBSCAN-SWA runs faster than any previous tools. Importantly, it has great detection power based on analysis using 184 manually curated prophages, with a recall of 85% compared with Phage_Finder (63%), VirSorter (74%), and PHASTER (82%) for (Multi-) FASTA sequences. Moreover, DBSCAN-SWA outperforms the existing standalone prophage prediction tools for high-throughput sequencing data based on the analysis of 19,989 contigs of 400 bacterial genomes collected from Human Microbiome Project (HMP) project. DBSCAN-SWA also provides user-friendly result visualizations including a circular prophage viewer and interactive DataTables. DBSCAN-SWA is implemented in Python3 and is available under an open source GPLv2 license from https://github.com/HIT-ImmunologyLab/DBSCAN-SWA/.

RevDate: 2022-10-18
CmpDate: 2022-08-09

Li D, Van De Werfhorst LC, PA Holden (2022)

Genetic sequence data evidence that human faecal-associated HF183 sequences are on human skin and in urine.

Journal of applied microbiology, 133(2):232-240.

AIMS: The DNA marker HF183 is a partial 16S rRNA gene sequence highly specific to human-associated Bacteroides including Bacteroides dorei. While HF183 is used to assess human faecal contamination in aquatic environments worldwide, little is known about the existence of HF183 and B. dorei in human microbiomes outside of the human gastrointestinal tract and faeces.

METHODS AND RESULTS: Previously published human skin and urine microbiome data sets from five independent human body skin studies, the Human Microbiome Project (HMP) and three independent human urine studies were analysed. The HF183 gene sequence was detected in all skin data sets, with the ratios of positive samples ranging from 0.5% to 36.3%. Popliteal fossa (knee), volar forearm and inguinal (groin) creases were identified as hot spots. HF183 was detected in two of three urine data sets, with ratios of positive samples ranging from 0% to 37.5%. All HF183-containing sequences from these data sets were classified as associated with B. dorei.

CONCLUSIONS: HF183 is widespread on human skin and present in urine.

Skin and urine microbiomes could be sources of HF183 to environmental waters. Such non-faecal sources of HF183 might explain low concentrations of HF183 in recreational waters when swimmers are present.

RevDate: 2023-03-22
CmpDate: 2022-12-21

Zhu Q, Huang S, Gonzalez A, et al (2022)

Phylogeny-Aware Analysis of Metagenome Community Ecology Based on Matched Reference Genomes while Bypassing Taxonomy.

mSystems, 7(2):e0016722.

We introduce the operational genomic unit (OGU) method, a metagenome analysis strategy that directly exploits sequence alignment hits to individual reference genomes as the minimum unit for assessing the diversity of microbial communities and their relevance to environmental factors. This approach is independent of taxonomic classification, granting the possibility of maximal resolution of community composition, and organizes features into an accurate hierarchy using a phylogenomic tree. The outputs are suitable for contemporary analytical protocols for community ecology, differential abundance, and supervised learning while supporting phylogenetic methods, such as UniFrac and phylofactorization, that are seldom applied to shotgun metagenomics despite being prevalent in 16S rRNA gene amplicon studies. As demonstrated in two real-world case studies, the OGU method produces biologically meaningful patterns from microbiome data sets. Such patterns further remain detectable at very low metagenomic sequencing depths. Compared with taxonomic unit-based analyses implemented in currently adopted metagenomics tools, and the analysis of 16S rRNA gene amplicon sequence variants, this method shows superiority in informing biologically relevant insights, including stronger correlation with body environment and host sex on the Human Microbiome Project data set and more accurate prediction of human age by the gut microbiomes of Finnish individuals included in the FINRISK 2002 cohort. We provide Woltka, a bioinformatics tool to implement this method, with full integration with the QIIME 2 package and the Qiita web platform, to facilitate adoption of the OGU method in future metagenomics studies. IMPORTANCE Shotgun metagenomics is a powerful, yet computationally challenging, technique compared to 16S rRNA gene amplicon sequencing for decoding the composition and structure of microbial communities. Current analyses of metagenomic data are primarily based on taxonomic classification, which is limited in feature resolution. To solve these challenges, we introduce operational genomic units (OGUs), which are the individual reference genomes derived from sequence alignment results, without further assigning them taxonomy. The OGU method advances current read-based metagenomics in two dimensions: (i) providing maximal resolution of community composition and (ii) permitting use of phylogeny-aware tools. Our analysis of real-world data sets shows that it is advantageous over currently adopted metagenomic analysis methods and the finest-grained 16S rRNA analysis methods in predicting biological traits. We thus propose the adoption of OGUs as an effective practice in metagenomic studies.

RevDate: 2022-10-25
CmpDate: 2022-04-05

Yu JSL, Correia-Melo C, Zorrilla F, et al (2022)

Microbial communities form rich extracellular metabolomes that foster metabolic interactions and promote drug tolerance.

Nature microbiology, 7(4):542-555.

Microbial communities are composed of cells of varying metabolic capacity, and regularly include auxotrophs that lack essential metabolic pathways. Through analysis of auxotrophs for amino acid biosynthesis pathways in microbiome data derived from >12,000 natural microbial communities obtained as part of the Earth Microbiome Project (EMP), and study of auxotrophic-prototrophic interactions in self-establishing metabolically cooperating yeast communities (SeMeCos), we reveal a metabolically imprinted mechanism that links the presence of auxotrophs to an increase in metabolic interactions and gains in antimicrobial drug tolerance. As a consequence of the metabolic adaptations necessary to uptake specific metabolites, auxotrophs obtain altered metabolic flux distributions, export more metabolites and, in this way, enrich community environments in metabolites. Moreover, increased efflux activities reduce intracellular drug concentrations, allowing cells to grow in the presence of drug levels above minimal inhibitory concentrations. For example, we show that the antifungal action of azoles is greatly diminished in yeast cells that uptake metabolites from a metabolically enriched environment. Our results hence provide a mechanism that explains why cells are more robust to drug exposure when they interact metabolically.

RevDate: 2022-10-21
CmpDate: 2022-03-31

Sharma AK, Davison S, Pafco B, et al (2022)

The primate gut mycobiome-bacteriome interface is impacted by environmental and subsistence factors.

NPJ biofilms and microbiomes, 8(1):12.

The gut microbiome of primates is known to be influenced by both host genetic background and subsistence strategy. However, these inferences have been made mainly based on adaptations in bacterial composition - the bacteriome and have commonly overlooked the fungal fraction - the mycobiome. To further understand the factors that shape the gut mycobiome of primates and mycobiome-bacteriome interactions, we sequenced 16 S rRNA and ITS2 markers in fecal samples of four different nonhuman primate species and three human groups under different subsistence patterns (n = 149). The results show that gut mycobiome composition in primates is still largely unknown but highly plastic and weakly structured by primate phylogeny, compared with the bacteriome. We find significant gut mycobiome overlap between captive apes and human populations living under industrialized subsistence contexts; this is in contrast with contemporary hunter-gatherers and agriculturalists, who share more mycobiome traits with diverse wild-ranging nonhuman primates. In addition, mycobiome-bacteriome interactions were specific to each population, revealing that individual, lifestyle and intrinsic ecological factors affect structural correspondence, number, and kind of interactions between gut bacteria and fungi in primates. Our findings indicate a dominant effect of ecological niche, environmental factors, and diet over the phylogenetic background of the host, in shaping gut mycobiome composition and mycobiome-bacteriome interactions in primates.

RevDate: 2022-04-20
CmpDate: 2022-04-20

Sisti D, Pazienza V, Piccini F, et al (2022)

A proposal for the reference intervals of the Italian microbiota "scaffold" in healthy adults.

Scientific reports, 12(1):3952.

Numerous factors, ranging from genetics, age, lifestyle, and dietary habits to local environments, contribute to the heterogeneity of the microbiota in humans. Understanding the variability of a "healthy microbiota" is a major challenge in scientific research. The gut microbiota profiles of 148 healthy Italian volunteers were examined by 16S rRNA gene sequencing to determine the range and diversity of taxonomic compositions in the gut microbiota of healthy populations. Possible driving factors were evaluated through a detailed anamnestic questionnaire. Microbiota reference intervals were also calculated. A "scaffold" of a healthy Italian gut microbiota composition was identified. Differences in relative quantitative ratios of microbiota composition were detected in two clusters: a bigger cluster (C2), which included 124 subjects, was characterized by more people from the northern Italian regions, who habitually practised more physical activity and with fewer dietary restrictions. Species richness and diversity were significantly higher in this cluster (C2) than in the other one (C1) (C1: 146.67 ± 43.67; C2: 198.17 ± 48.47; F = 23.40; P < 0.001 and C1: 16.88 ± 8.66; C2: 35.01 ± 13.40; F = 40.50; P < 0.001, respectively). The main contribution of the present study was the identification of the existence of a primary healthy microbiological framework that is only marginally affected by variations. Taken together, our data help to contextualize studies on population-specific variations, including marginal aspects, in human microbiota composition. Such variations must be related to the primary framework of a healthy microbiota and providing this perspective could help scientists to better design experimental plans and develop strategies for precision tailored microbiota modulation.

RevDate: 2022-10-25
CmpDate: 2022-03-31

Cai YY, Huang FQ, Lao X, et al (2022)

Integrated metagenomics identifies a crucial role for trimethylamine-producing Lachnoclostridium in promoting atherosclerosis.

NPJ biofilms and microbiomes, 8(1):11.

Microbial trimethylamine (TMA)-lyase activity promotes the development of atherosclerosis by generating of TMA, the precursor of TMA N-oxide (TMAO). TMAO is well documented, but same can not be said of TMA-producing bacteria. This work aimed to identify TMA-producing genera in human intestinal microbiota. We retrieved the genomes of human-associated microorganisms from the Human Microbiome Project database comprising 1751 genomes, Unified Human Gastrointestinal Genome collection consisting 4644 gut prokaryotes, recapitulated 4930 species-level genome bins and public gut metagenomic data of 2134 individuals from 11 populations. By sequence searching, 216 TMA-lyase-containing species from 102 genera were found to contain the homologous sequences of cntA/B, yeaW/X, and/or cutC/D. We identified 13 strains from 5 genera with cntA sequences, and 30 strains from 14 genera with cutC showing detectable relative abundance in healthy individuals. Lachnoclostridium (p = 2.9e-05) and Clostridium (p = 5.8e-04), the two most abundant cutC-containing genera, were found to be much higher in atherosclerotic patients compared with healthy persons. Upon incubation with choline (substrate), L. saccharolyticum effectively transformed it to TMA at a rate higher than 98.7% while that for C. sporogenes was 63.8-67.5% as detected by liquid chromatography-triple quadrupole mass spectrometry. In vivo studies further showed that treatment of L. saccharolyticum and choline promoted a significant increase in TMAO level in the serum of ApoE[-/-] mice with obvious accumulation of aortic plaque in same. This study discloses the significance and efficiency of the gut bacterium L. saccharolyticum in transforming choline to TMA and consequently promoting the development of atherosclerosis.

RevDate: 2023-01-24
CmpDate: 2022-12-26

Zhou F, Gan R, Zhang F, et al (2022)

PHISDetector: A Tool to Detect Diverse In Silico Phage-host Interaction Signals for Virome Studies.

Genomics, proteomics & bioinformatics, 20(3):508-523.

Phage-microbe interactions are appealing systems to study coevolution, and have also been increasingly emphasized due to their roles in human health, disease, and the development of novel therapeutics. Phage-microbe interactions leave diverse signals in bacterial and phage genomic sequences, defined as phage-host interaction signals (PHISs), which include clustered regularly interspaced short palindromic repeats (CRISPR) targeting, prophage, and protein-protein interaction signals. In the present study, we developed a novel tool phage-host interaction signal detector (PHISDetector) to predict phage-host interactions by detecting and integrating diverse in silico PHISs, and scoring the probability of phage-host interactions using machine learning models based on PHIS features. We evaluated the performance of PHISDetector on multiple benchmark datasets and application cases. When tested on a dataset of 758 annotated phage-host pairs, PHISDetector yields the prediction accuracies of 0.51 and 0.73 at the species and genus levels, respectively, outperforming other phage-host prediction tools. When applied to on 125,842 metagenomic viral contigs (mVCs) derived from 3042 geographically diverse samples, a detection rate of 54.54% could be achieved. Furthermore, PHISDetector could predict infecting phages for 85.6% of 368 multidrug-resistant (MDR) bacteria and 30% of 454 human gut bacteria obtained from the National Institutes of Health (NIH) Human Microbiome Project (HMP). The PHISDetector can be run either as a web server (http://www.microbiome-bigdata.com/PHISDetector/) for general users to study individual inputs or as a stand-alone version (https://github.com/HIT-ImmunologyLab/PHISDetector) to process massive phage contigs from virome studies.

RevDate: 2022-11-09
CmpDate: 2022-03-02

Johansen J, Plichta DR, Nissen JN, et al (2022)

Genome binning of viral entities from bulk metagenomics data.

Nature communications, 13(1):965.

Despite the accelerating number of uncultivated virus sequences discovered in metagenomics and their apparent importance for health and disease, the human gut virome and its interactions with bacteria in the gastrointestinal tract are not well understood. This is partly due to a paucity of whole-virome datasets and limitations in current approaches for identifying viral sequences in metagenomics data. Here, combining a deep-learning based metagenomics binning algorithm with paired metagenome and metavirome datasets, we develop Phages from Metagenomics Binning (PHAMB), an approach that allows the binning of thousands of viral genomes directly from bulk metagenomics data, while simultaneously enabling clustering of viral genomes into accurate taxonomic viral populations. When applied on the Human Microbiome Project 2 (HMP2) dataset, PHAMB recovered 6,077 high-quality genomes from 1,024 viral populations, and identified viral-microbial host interactions. PHAMB can be advantageously applied to existing and future metagenomes to illuminate viral ecological dynamics with other microbiome constituents.

RevDate: 2022-12-07
CmpDate: 2022-04-27

Zhang R, Sun J, Wang C, et al (2021)

The Racial Disparities in the Epidemic of Metabolic Syndrome With Increased Age: A Study From 28,049 Chinese and American Adults.

Frontiers in public health, 9:797183.

BACKGROUND: Previous studies have revealed ethnic disparities in the prevalence of metabolic syndrome (MetS); however, the literature regarding aging-related patterns of disparities in MetS and its components remains limited.

METHODS: This cross-sectional study recruited 28,049 subjects, consisting of one Chinese race and three American races, 18-85 years of age, from the National Health and Nutrition Examination Survey (NHANES, 1999-2018) of the United States, and the Guangdong Gut Microbiome Project (GGMP, 2018) of China. MetS was defined in accordance with the National Cholesterol Education Program Adult Treatment Panel III. A modified sliding-window-based algorithm was used to depict the trajectories of the prevalence of MetS with increased age. Logistic regression analysis was performed to investigate associations between MetS and its components.

RESULTS: The prevalence of MetS increased non-linearly with age, with growth speed reaching its maximum at approximately 40-50 years. Chinese subjects exhibited a lower prevalence of MetS than non-Hispanic whites, non-Hispanic blacks, and Mexican Americans in all age groups. The two most prevalent components in Chinese subjects were reduced high-density lipoprotein cholesterol levels (42.0%) and elevated blood pressure (49.5%), and elevated triglyceride levels (36.3-49.5%) and abdominal obesity (55.8-55.9%) in Americans. Before 40 years of age, the top two MetS-associated components were abdominal obesity and elevated triglyceride levels in all races, while after 40 years, the prominent associations between MetS and its components varied among the different races and age groups.

CONCLUSIONS: Although racial disparities in the epidemic of MetS varied with increased age, abdominal obesity and elevated triglyceride levels were the top two MetS-associated components in all younger adults of different races.

RevDate: 2022-05-19
CmpDate: 2022-05-19

Mandal S, Bandyopadhyay S, Tyagi K, et al (2022)

Human microbial dysbiosis as driver of gynecological malignancies.

Biochimie, 197:86-95.

Gynecological cancers that affect female reproductive tract, remain at the top of the global cancer burden list with high relapse rate and mortality. Notwithstanding development of several novel therapeutic interventions including poly-ADP-ribose polymerase inhibitors, this family of malignancies remain deadly. The human microbiome project demonstrated that dysbiosis of health resident microflora is associated with several pathologies including malignancies of the female reproductive tract and detailed characterization of species variation and host-microbe interaction could provide clues for identification of early diagnostic biomarker, preventive and therapeutic interventions. Emerging evidence suggests that several microbial signatures are significantly associated with gynecological cancers. An increased population of Proteobacteria and Firmicutes followed by significantly reduced Lactobacilli are associated with lethal epithelial ovarian cancer. Similarly, a constant association of elevated level of Atopobium vaginae, Porphyromonas somerae, Micrococci and Gardnerella vaginalis are observed in endometrial and cervical cancers. Moreover, human papilloma virus infection significantly augments colonization of pathogenic microbes including Sneathia sanguinegens, Anaerococcus tetradius, and Peptostreptococcus anaerobius and drives carcinoma of the cervix. Interestingly, microbial dysbiosis in female reproductive tract modulates expression of several microbial and immune-responsive genes such as TLR-4, TLR-5, TLR-6 and NOD-1. Therefore, stringent investigation into the microbial dysbiosis and its underlying mechanism could provide valuable cues for identification of early diagnostic biomarker, preventive and therapeutic interventions against rogue gynecological malignancies.

RevDate: 2022-11-07
CmpDate: 2022-02-25

Lopera-Maya EA, Kurilshikov A, van der Graaf A, et al (2022)

Effect of host genetics on the gut microbiome in 7,738 participants of the Dutch Microbiome Project.

Nature genetics, 54(2):143-151.

Host genetics are known to influence the gut microbiome, yet their role remains poorly understood. To robustly characterize these effects, we performed a genome-wide association study of 207 taxa and 205 pathways representing microbial composition and function in 7,738 participants of the Dutch Microbiome Project. Two robust, study-wide significant (P < 1.89 × 10[-10]) signals near the LCT and ABO genes were found to be associated with multiple microbial taxa and pathways and were replicated in two independent cohorts. The LCT locus associations seemed modulated by lactose intake, whereas those at ABO could be explained by participant secretor status determined by their FUT2 genotype. Twenty-two other loci showed suggestive evidence (P < 5 × 10[-8]) of association with microbial taxa and pathways. At a more lenient threshold, the number of loci we identified strongly correlated with trait heritability, suggesting that much larger sample sizes are needed to elucidate the remaining effects of host genetics on the gut microbiome.

RevDate: 2022-10-25
CmpDate: 2022-04-19

Saliba J, Coutaud B, Makhani K, et al (2022)

Loss of NFE2L3 protects against inflammation-induced colorectal cancer through modulation of the tumor microenvironment.

Oncogene, 41(11):1563-1575.

We investigated the role of the NFE2L3 transcription factor in inflammation-induced colorectal cancer. Our studies revealed that Nfe2l3[-/-] mice exhibit significantly less inflammation in the colon, reduced tumor size and numbers, and skewed localization of tumors with a more pronounced decrease of tumors in the distal colon. CIBERSORT analysis of RNA-seq data from normal and tumor tissue predicted a reduction in mast cells in Nfe2l3[-/-] animals, which was confirmed by toluidine blue staining. Concomitantly, the transcript levels of Il33 and Rab27a, both important regulators of mast cells, were reduced and increased, respectively, in the colorectal tumors of Nfe2l3[-/-] mice. Furthermore, we validated NFE2L3 binding to the regulatory sequences of the IL33 and RAB27A loci in human colorectal carcinoma cells. Using digital spatial profiling, we found that Nfe2l3[-/-] mice presented elevated FOXP3 and immune checkpoint markers CTLA4, TIM3, and LAG3, suggesting an increase in Treg counts. Staining for CD3 and FOXP3 confirmed a significant increase in immunosuppressive Tregs in the colon of Nfe2l3[-/-] animals. Also, Human Microbiome Project (HMP2) data showed that NFE2L3 transcript levels are higher in the rectum of ulcerative colitis patients. The observed changes in the tumor microenvironment provide new insights into the molecular differences regarding colon cancer sidedness. This may be exploited for the treatment of early-onset colorectal cancer as this emerging subtype primarily displays distal/left-sided tumors.

RevDate: 2022-02-08
CmpDate: 2022-02-02

Su Z, Jia X, Fan Y, et al (2022)

[Progress of Research on the Relationship between Lung Microbiome and Lung Cancer].

Zhongguo fei ai za zhi = Chinese journal of lung cancer, 25(1):40-45.

The microbiota plays an important role in the biological functions of the human body and is associated with various disease states such as inflammation (gastritis, hepatitis) and cancer (stomach, cervical, liver). The Human Microbiome Project painted a panorama of human microorganisms in its first phase, incorporating body parts such as the nasal cavity, oral cavity, intestine, vagina and skin, while the lungs were considered a sterile environment. However, studies in recent years have confirmed the presence of a rich microbial community in the lung, and the association of this lung microbiota with lung disease has become a hot topic of research. Current research has found that patients with lung cancer have a specific microbiota compared to healthy individuals or patients with lung disease. Even in patients with lung cancer, a lung microbiota specific to the tumor site is present. In addition, different pathological types and metastatic status of lung cancer can lead to differences in microbiota. Mechanistic studies have found that the lung microbiota may influence lung cancer development by affecting the immune response. Clinical studies on lung microbiota and immunotherapy are still in the preliminary stage. More relevant studies are needed in the future to provide high-quality evidence to further understand the oncogenic mechanisms of lung microbiota and provide new ideas for clinical treatment. This paper briefly reviews the progress of lung microbiota research in terms of its relevance to lung cancer, possible molecular mechanisms and applications in clinical treatment, and provides an outlook for future research. .

RevDate: 2022-01-22

Liu B, Huang L, Liu Z, et al (2021)

EasyMicroPlot: An Efficient and Convenient R Package in Microbiome Downstream Analysis and Visualization for Clinical Study.

Frontiers in genetics, 12:803627.

Advances in next-generation sequencing (NGS) have revolutionized microbial studies in many fields, especially in clinical investigation. As the second human genome, microbiota has been recognized as a new approach and perspective to understand the biological and pathologic basis of various diseases. However, massive amounts of sequencing data remain a huge challenge to researchers, especially those who are unfamiliar with microbial data analysis. The mathematic algorithm and approaches introduced from another scientific field will bring a bewildering array of computational tools and acquire higher quality of script experience. Moreover, a large cohort research together with extensive meta-data including age, body mass index (BMI), gender, medical results, and others related to subjects also aggravate this situation. Thus, it is necessary to develop an efficient and convenient software for clinical microbiome data analysis. EasyMicroPlot (EMP) package aims to provide an easy-to-use microbial analysis tool based on R platform that accomplishes the core tasks of metagenomic downstream analysis, specially designed by incorporation of popular microbial analysis and visualization used in clinical microbial studies. To illustrate how EMP works, 694 bio-samples from Guangdong Gut Microbiome Project (GGMP) were selected and analyzed with EMP package. Our analysis demonstrated the influence of dietary style on gut microbiota and proved EMP package's powerful ability and excellent convenience to address problems for this field.

RevDate: 2022-01-28

Gouello A, Dunyach-Remy C, Siatka C, et al (2021)

Analysis of Microbial Communities: An Emerging Tool in Forensic Sciences.

Diagnostics (Basel, Switzerland), 12(1):.

The objective of forensic sciences is to find clues in a crime scene in order to reconstruct the scenario. Classical samples include DNA or fingerprints, but both have inherent limitations and can be uninformative. Another type of sample has emerged recently in the form of the microbiome. Supported by the Human Microbiome Project, the characteristics of the microbial communities provide real potential in forensics. They are highly specific and can be used to differentiate and classify the originating body site of a human biological trace. Skin microbiota is also highly specific and different between individuals, leading to its possibility as an identification tool. By extension, the possibilities of the microbial communities to be deposited on everyday objects has also been explored. Other uses include the determination of the post-mortem interval or the analysis of soil communities. One challenge is that the microbiome changes over time and can be influenced by many environmental and lifestyle factors. This review offers an overview of the main methods and applications to demonstrate the benefit of the microbiome to provide forensically relevant information.

RevDate: 2022-02-03
CmpDate: 2022-02-03

Popkov VA, Zharikova AA, Demchenko EA, et al (2022)

Gut Microbiota as a Source of Uremic Toxins.

International journal of molecular sciences, 23(1):.

Uremic retention solutes are the compounds that accumulate in the blood when kidney excretory function is impaired. Some of these compounds are toxic at high concentrations and are usually known as "uremic toxins". The cumulative detrimental effect of uremic toxins results in numerous health problems and eventually mortality during acute or chronic uremia, especially in end-stage renal disease. More than 100 different solutes increase during uremia; however, the exact origin for most of them is still debatable. There are three main sources for such compounds: exogenous ones are consumed with food, whereas endogenous ones are produced by the host metabolism or by symbiotic microbiota metabolism. In this article, we identify uremic retention solutes presumably of gut microbiota origin. We used database analysis to obtain data on the enzymatic reactions in bacteria and human organisms that potentially yield uremic retention solutes and hence to determine what toxins could be synthesized in bacteria residing in the human gut. We selected biochemical pathways resulting in uremic retention solutes synthesis related to specific bacterial strains and revealed links between toxin concentration in uremia and the proportion of different bacteria species which can synthesize the toxin. The detected bacterial species essential for the synthesis of uremic retention solutes were then verified using the Human Microbiome Project database. Moreover, we defined the relative abundance of human toxin-generating enzymes as well as the possibility of the synthesis of a particular toxin by the human metabolism. Our study presents a novel bioinformatics approach for the elucidation of the origin of both uremic retention solutes and uremic toxins and for searching for the most likely human microbiome producers of toxins that can be targeted and used for the therapy of adverse consequences of uremia.

RevDate: 2022-01-07

Stanislawski MA, Stamper CE, Stearns-Yoder KA, et al (2021)

Characterization of the gut microbiota among Veterans with unique military-related exposures and high prevalence of chronic health conditions: A United States-Veteran Microbiome Project (US-VMP) study.

Brain, behavior, & immunity - health, 18:100346.

The gut microbiome is impacted by environmental exposures and has been implicated in many physical and mental health conditions, including anxiety disorders, affective disorders, and trauma- and stressor-related disorders such as posttraumatic stress disorder (PTSD). United States (US) military Veterans are a unique population in that their military-related exposures can have consequences for both physical and mental health, but the gut microbiome of this population has been understudied. In this publication, we describe exposures, health conditions, and medication use of Veterans in the US Veteran Microbiome Project (US-VMP) and examine the associations between these characteristics and the gut microbiota. This cohort included 331 US Veterans seeking healthcare with the Veterans Health Administration who were 83% male with an average (±SD) age of 47.6 ± 13.4 years. The cohort displayed a high prevalence of PTSD (49.8%) and history of traumatic brain injuries (76.1%), and high current use of prescription medications (74.9%) to treat various acute and chronic conditions. We observed significant associations between the gut microbiota composition and gastroenteritis, peripheral vascular disease (PVD), bipolar disorders, symptoms of severe depression based on the Beck Depression Inventory, stimulant and opioid use disorders, beta-blockers, serotonin and norepinephrine reuptake inhibitor antidepressants, diabetes medications, and proton pump inhibitors. Many of the Veteran characteristics examined were associated with altered relative abundances of specific taxa. We found that PVD and cardiovascular disease were associated with lower microbiota diversity in the gut (i.e., α-diversity), while supplemental vitamin use was associated with higher α-diversity. Our study contributes novel insights as to whether the unique exposures of Veterans in this cohort correlate with gut microbiota characteristics and, in line with previous findings with other population-level studies of the microbiome, confirms associations between numerous health conditions and medications with the gut microbiome.

RevDate: 2022-05-05
CmpDate: 2022-05-05

Fromentin M, Bridier-Nahmias A, Legoff J, et al (2022)

The 16S rRNA lung microbiome in mechanically ventilated patients: a methodological study.

Experimental lung research, 48(1):23-34.

Characterization of the respiratory tract bacterial microbiome is in its infancy when compared to the gut microbiota. To limit bias mandates a robust methodology. Specific amplification of the hypervariable (V) region of the 16SrRNA gene is a crucial step. Differences in accuracy exist for one V region to another depending on the sampled environment. We aimed to assess the impact of the primer sequences targeting the V4 region currently used for gut microbiota studies in respiratory samples. Materials and methods: The original 515 F-806R primer pair targets the V4 region of the 16SrRNA gene. We compared two different 515 F-806R primer pairs before Illumina 250 paired-end sequencing for bacterial microbiome analyses of respiratory samples from critically-ill ventilated patients. "S-V4" for "Stringent V4" primer pair is used in two ongoing international projects "the Integrative Human microbiome project (iHMP)" and "the Earth microbiome project (EMP)." "R-V4" for "Relaxed V4" primer pair has been modified to reduce biases against specific environmental taxa. The optimal method was determined by concordance with conventional microbiology. Results: Twenty samples from three patients who developed a ventilator-associated pneumonia (VAP) and four who did not (control ventilated patients) were sequenced. Highly different results were obtained. "S-V4" provided the best agreement with the conventional microbiology for endotracheal aspirate: 89% as compared to 56% for "R-V4." The main difference related to poor Enterobacteriaceae detection with "R-V4" primers. Conclusions: Accuracy of the bacterial lung microbiome composition was highly dependent on the primers used for amplification of the 16 s rRNA hypervariable sequence. This work validates for future lung microbiome studies the use of the 515 F-806R "S-V4" primer pair associated to Illumina® MiSeq paired-end sequencing.

RevDate: 2021-12-28

Eschweiler K, Clayton JB, Moresco A, et al (2021)

Host Identity and Geographic Location Significantly Affect Gastrointestinal Microbial Richness and Diversity in Western Lowland Gorillas (Gorilla gorilla gorilla) under Human Care.

Animals : an open access journal from MDPI, 11(12):.

The last few decades have seen an outpouring of gastrointestinal (GI) microbiome studies across diverse host species. Studies have ranged from assessments of GI microbial richness and diversity to classification of novel microbial lineages. Assessments of the "normal" state of the GI microbiome composition across multiple host species has gained increasing importance for distinguishing healthy versus diseased states. This study aimed to determine baselines and trends over time to establish "typical" patterns of GI microbial richness and diversity, as well as inter-individual variation, in three populations of western lowland gorillas (Gorilla gorilla gorilla) under human care at three zoological institutions in North America. Fecal samples were collected from 19 western lowland gorillas every two weeks for seven months (n = 248). Host identity and host institution significantly affected GI microbiome community composition (p < 0.05), although host identity had the most consistent and significant effect on richness (p = 0.03) and Shannon diversity (p = 0.004) across institutions. Significant changes in microbial abundance over time were observed only at Denver Zoo (p < 0.05). Our results suggest that individuality contributes to most of the observed GI microbiome variation in the study populations. Our results also showed no significant changes in any individual's microbial richness or Shannon diversity during the 7-month study period. While some microbial taxa (Prevotella, Prevotellaceae and Ruminococcaceae) were detected in all gorillas at varying levels, determining individual baselines for microbial composition comparisons may be the most useful diagnostic tool for optimizing non-human primate health under human care.

RevDate: 2022-07-16
CmpDate: 2022-03-18

Ghannoum MA, McCormick TS, Retuerto M, et al (2021)

Evaluation of Microbiome Alterations Following Consumption of BIOHM, a Novel Probiotic.

Current issues in molecular biology, 43(3):2135-2146.

Gastrointestinal microbiome dysbiosis may result in harmful effects on the host, including those caused by inflammatory bowel diseases (IBD). The novel probiotic BIOHM, consisting of Bifidobacterium breve, Saccharomyces boulardii, Lactobacillus acidophilus, L. rhamnosus, and amylase, was developed to rebalance the bacterial-fungal gut microbiome, with the goal of reducing inflammation and maintaining a healthy gut population. To test the effect of BIOHM on human subjects, we enrolled a cohort of 49 volunteers in collaboration with the Fermentation Festival group (Santa Barbara, CA, USA). The profiles of gut bacterial and fungal communities were assessed via stool samples collected at baseline and following 4 weeks of once-a-day BIOHM consumption. Mycobiome analysis following probiotic consumption revealed an increase in Ascomycota levels in enrolled individuals and a reduction in Zygomycota levels (p value < 0.01). No statistically significant difference in Basidiomycota was detected between pre- and post-BIOHM samples and control abundance profiles (p > 0.05). BIOHM consumption led to a significant reduction in the abundance of Candida genus in tested subjects (p value < 0.013), while the abundance of C. albicans also trended lower than before BIOHM use, albeit not reaching statistical significance. A reduction in the abundance of Firmicutes at the phylum level was observed following BIOHM use, which approached levels reported for control individuals reported in the Human Microbiome Project data. The preliminary results from this clinical study suggest that BIOHM is capable of significantly rebalancing the bacteriome and mycobiome in the gut of healthy individuals, suggesting that further trials examining the utility of the BIOHM probiotic in individuals with gastrointestinal symptoms, where dysbiosis is considered a source driving pathogenesis, are warranted.

RevDate: 2022-01-08
CmpDate: 2021-12-22

Verstraelen H, Vieira-Baptista P, De Seta F, et al (2022)

The Vaginal Microbiome: I. Research Development, Lexicon, Defining "Normal" and the Dynamics Throughout Women's Lives.

Journal of lower genital tract disease, 26(1):73-78.

OBJECTIVE: This series of articles, titled The Vaginal Microbiome, written on behalf of the International Society for the Study of Vulvovaginal Disease, aims to summarize the current findings and understanding of the vaginal bacterial microbiota, mainly regarding areas relevant to clinicians specializing in vulvovaginal disorders.

MATERIALS AND METHODS: A database search of PubMed was performed, using the search terms "vaginal microbiome" (VMB) with "research," "normal," "neonate," "puberty," "adolescent," "menopause," and "ethnicities," as well as "human microbiome project." Full article texts were reviewed. Reference lists were screened for additional articles.

RESULTS: In the last 2 decades, many studies applying molecular techniques were performed, intending to characterize the vaginal microbiota. These studies advanced our understanding of how vaginal health is defined. The first article in this series focuses on the advancement of VMB research, technical definitions, the definition of "normal" VMB, and the dynamics of VMB throughout women's lives.

CONCLUSIONS: Understanding how microorganisms inhabiting the vagina interact with each other and with the host is important for a more complete understanding of vaginal health. The clinical application of microbial community sequencing is in its beginning, and its interpretation regarding practical clinical aspects is yet to be determined.

RevDate: 2022-04-29

Barb JJ, Maki KA, Kazmi N, et al (2022)

The oral microbiome in alcohol use disorder: a longitudinal analysis during inpatient treatment.

Journal of oral microbiology, 14(1):2004790.

BACKGROUND: Alcohol use disorder (AUD)-induced disruption of oral microbiota can lead to poor oral health; there have been no studies published examining the longitudinal effects of alcohol use cessation on the oral microbiome.

AIM: To investigate the oral microbiome during alcohol cessation during inpatient treatment for AUD.

METHODS: Up to 10 oral tongue brushings were collected from 22 AUD patients during inpatient treatment at the National Institutes of Health. Alcohol use history, smoking, and periodontal disease status were measured. Oral microbiome samples were sequenced using 16S rRNA gene sequencing.

RESULTS: Alpha diversity decreased linearly during treatment across the entire cohort (P = 0.002). Alcohol preference was associated with changes in both alpha and beta diversity measures. Characteristic tongue dorsum genera from the Human Microbiome Project such as Streptococcus, Prevotella, Veillonella and Haemophilus were highly correlated in AUD. Oral health-associated genera that changed longitudinally during abstinence included Actinomyces, Capnocytophaga, Fusobacterium, Neisseria and Prevotella.

CONCLUSION: The oral microbiome in AUD is affected by alcohol preference. Patients with AUD often have poor oral health but abstinence and attention to oral care improve dysbiosis, decreasing microbiome diversity and periodontal disease-associated genera while improving acute oral health.

RevDate: 2021-12-22

Zhang Z, Liu Y, Zhang P, et al (2021)

PAAR Proteins Are Versatile Clips That Enrich the Antimicrobial Weapon Arsenals of Prokaryotes.

mSystems, 6(6):e0095321.

Protein toxins secreted by prokaryotes have been found to affect the pathogenicity of pathogens or directly mediate antagonistic interactions between prokaryotes. PAAR proteins are important carriers of toxic effectors and are located at the forefront of either the type VI secretion system (T6SS) or the extracellular contractile injection system (eCIS). This study systematically investigated PAAR homologues and related toxic effectors. We found that PAAR homologues were divided into 8 types and 16 subtypes and distributed in 23.1% of bacterial genomes and 7.8% of archaeal genomes. PAAR proteins of all types fold into a highly similar conical structure, even from relatively diverse underlying sequences. PAAR homologues associated with different secretion systems display a mixed phylogenetic relationship, indicating that PAAR proteins from such a subtype can be assembled on either a T6SS or an eCIS. More than 1,300 PAAR-related toxic effector genes were identified; one PAAR subtype can be associated with toxins of over 40 families, and toxins from one family can be associated with more than 10 PAAR subtypes. A large-scale comparison of Earth Microbiome Project data and prokaryotic genomes revealed that prokaryotes encoding PAAR genes are widely present in diverse environments worldwide, and taxa encoding multiple PAAR gene copies exhibit a wider distribution in environments than other taxa. Overall, our studies highlighted that PAAR proteins are versatile clips loaded with antimicrobial toxin bullets for secretion weapons (T6SS and eCIS), greatly enriching the weapon arsenal of prokaryotes, which, often together with VgrG, help prokaryotes fight for survival advantages in crowded environments. IMPORTANCE Infectious diseases caused by microbial pathogens are severe threats to human health and economic development. To respond to these threats, it is necessary to understand how microorganisms survive in and adapt to complex environments. Microorganic toxins, which are widely distributed in nature, are the key weapons in life domain interactions. PAAR proteins are important carriers of prokaryotic toxic effectors. We reveal the versatility of PAAR proteins between secretory systems and the massive diversity of toxic effectors carried by PAAR proteins, which helps prokaryotes enrich their arsenal and expand their ability to attack their neighbors. A large number of PAAR homologues and related toxic effectors enhance the survival competitiveness of prokaryotic populations. In conclusion, our work provides an example for large-scale analysis of the global distribution and ecological functions of prokaryotic functional genes.


RJR Experience and Expertise


Robbins holds BS, MS, and PhD degrees in the life sciences. He served as a tenured faculty member in the Zoology and Biological Science departments at Michigan State University. He is currently exploring the intersection between genomics, microbial ecology, and biodiversity — an area that promises to transform our understanding of the biosphere.


Robbins has extensive experience in college-level education: At MSU he taught introductory biology, genetics, and population genetics. At JHU, he was an instructor for a special course on biological database design. At FHCRC, he team-taught a graduate-level course on the history of genetics. At Bellevue College he taught medical informatics.


Robbins has been involved in science administration at both the federal and the institutional levels. At NSF he was a program officer for database activities in the life sciences, at DOE he was a program officer for information infrastructure in the human genome project. At the Fred Hutchinson Cancer Research Center, he served as a vice president for fifteen years.


Robbins has been involved with information technology since writing his first Fortran program as a college student. At NSF he was the first program officer for database activities in the life sciences. At JHU he held an appointment in the CS department and served as director of the informatics core for the Genome Data Base. At the FHCRC he was VP for Information Technology.


While still at Michigan State, Robbins started his first publishing venture, founding a small company that addressed the short-run publishing needs of instructors in very large undergraduate classes. For more than 20 years, Robbins has been operating The Electronic Scholarly Publishing Project, a web site dedicated to the digital publishing of critical works in science, especially classical genetics.


Robbins is well-known for his speaking abilities and is often called upon to provide keynote or plenary addresses at international meetings. For example, in July, 2012, he gave a well-received keynote address at the Global Biodiversity Informatics Congress, sponsored by GBIF and held in Copenhagen. The slides from that talk can be seen HERE.


Robbins is a skilled meeting facilitator. He prefers a participatory approach, with part of the meeting involving dynamic breakout groups, created by the participants in real time: (1) individuals propose breakout groups; (2) everyone signs up for one (or more) groups; (3) the groups with the most interested parties then meet, with reports from each group presented and discussed in a subsequent plenary session.


Robbins has been engaged with photography and design since the 1960s, when he worked for a professional photography laboratory. He now prefers digital photography and tools for their precision and reproducibility. He designed his first web site more than 20 years ago and he personally designed and implemented this web site. He engages in graphic design as a hobby.

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For most of human existence, microbes were hidden, visible only through the illnesses they caused. When they finally surfaced in biological studies, they were cast as rogues. Only recently have they immigrated from the neglected fringes of biology to its center. Even today, many people think of microbes as germs to be eradicated, but those that live with us — the microbiome — are invaluable parts of our lives. I Contain Multitudes lets us peer into that world for the first time, allowing us to see how ubiquitous and vital microbes are: they sculpt our organs, defend us from disease, break down our food, educate our immune systems, guide our behavior, bombard our genomes with their genes, and grant us incredible abilities.

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Collection of publications by R J Robbins

Reprints and preprints of publications, slide presentations, instructional materials, and data compilations written or prepared by Robert Robbins. Most papers deal with computational biology, genome informatics, using information technology to support biomedical research, and related matters.

Research Gate page for R J Robbins

ResearchGate is a social networking site for scientists and researchers to share papers, ask and answer questions, and find collaborators. According to a study by Nature and an article in Times Higher Education , it is the largest academic social network in terms of active users.

Curriculum Vitae for R J Robbins

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Curriculum Vitae for R J Robbins

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