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20 Jan 2019 at 01:40
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Bibliography on: Human Microbiome


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RJR: Recommended Bibliography 20 Jan 2019 at 01:40 Created: 

Human Microbiome

The human microbiome is the set of all microbes that live on or in humans. Together, a human body and its associated microbiomes constitute a human holobiont. Although a human holobiont is mostly mammal by weight, by cell count it is mostly microbial. The number of microbial genes in the associated microbiomes far outnumber the number of human genes in the human genome. Just as humans (and other multicellular eukaryotes) evolved in the constant presence of gravity, so they also evolved in the constant presence of microbes. Consequently, nearly every aspect of human biology has evolved to deal with, and to take advantage of, the existence of associated microbiota. In some cases, the absence of a "normal microbiome" can cause disease, which can be treated by the transplant of a correct microbiome from a healthy donor. For example, fecal transplants are an effective treatment for chronic diarrhea from over abundant Clostridium difficile bacteria in the gut.

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

Citations The Papers (from PubMed®)

RevDate: 2019-01-18

Pellock SJ, Walton WG, Ervin SM, et al (2019)

Discovery and Characterization of FMN-Binding β-Glucuronidases in the Human Gut Microbiome.

Journal of molecular biology pii:S0022-2836(19)30011-7 [Epub ahead of print].

The human gut microbiota encodes β-glucuronidases (GUS) that play key roles in health and disease via the metabolism of glucuronate-containing carbohydrates and drugs. Hundreds of putative bacterial GUS enzymes have been identified by metagenomic analysis of the human gut microbiome, but less than 10% have characterized structures and functions. Here we describe a set of unique gut microbial GUS enzymes that bind flavin mononucleotide (FMN). First, we show using mass spectrometry, isothermal titration calorimetry, and x-ray crystallography that a purified GUS from the gut commensal microbe Faecalibacterium prausnitzii binds to FMN on a surface groove located 30 Å away from the active site. Second, utilizing structural and functional data from this FMN-binding GUS, we analyzed the 279 unique GUS sequences from the human microbiome project database and identified 14 putative FMN-binding GUSs. We characterized four of these hits and solved the structure of two, the GUSs from Ruminococcus gnavus and Roseburia hominis, which confirmed that these are FMN binders. Third, binding and kinetic analysis of the FMN-binding site mutants of these five GUSs show that they utilize a conserved site to bind FMN that is not essential for GUS activity, but can affect KM. Lastly, a comprehensive structural review of the PDB reveals that the FMN-binding site employed by these enzymes is unlike any structurally characterized FMN-binders to date. These findings reveal the first instance of an FMN-binding glycoside hydrolase and suggest a potential link between FMN and carbohydrate metabolism in the human gut microbiota.

RevDate: 2019-01-18

Espin-Garcia O, Croitoru K, W Xu (2019)

A finite mixture model for X-chromosome association with an emphasis on microbiome data analysis.

Genetic epidemiology [Epub ahead of print].

Analysis of the X chromosome has been largely neglected in genetic studies mainly because of complex underlying biological mechanisms. On the other hand, the study of human microbiome data (typically over-dispersed counts with an excess of zeros) has generated great interest recently because of advancements in next-generation sequencing technologies. We propose a novel approach to infer the association between host genetic variants in the X-chromosome and microbiome data. The method accounts for random X-chromosome inactivation (XCI), skewed (or nonrandom) XCI (XCI-S), and escape of XCI (XCI-E). The inference is performed through a finite mixture model (FMM), in which an indicator variable denoting the "true" biological mechanism is treated as missing data. An expectation-maximization algorithm on zero-inflated and two-part models is implemented to estimate genetic effects. We investigate the performance of the FMM along with strategies that assume XCI and XCI-E mechanisms for all subjects compared with alternative approaches. Briefly, an XCI mechanism codes males' genotypes as homozygous females, whereas under XCI-E, males are treated as heterozygous females. By comprehensive simulations, we evaluate tests of the hypothesis under a computationally efficient score statistic. In summary, the FMM renders reduced bias and commensurate power compared to XCI, XCI-E, and alternative strategies while maintaining adequate Type 1 error control. The proposed method has far-reaching applications. In particular, we illustrate its usage on a large-scale human microbiome study, the Genetic, Environmental and Microbial (GEM) project, to test for the genetic association on the X chromosome.

RevDate: 2019-01-16

Britton GJ, Contijoch EJ, Mogno I, et al (2019)

Microbiotas from Humans with Inflammatory Bowel Disease Alter the Balance of Gut Th17 and RORγt+ Regulatory T Cells and Exacerbate Colitis in Mice.

Immunity, 50(1):212-224.e4.

Microbiota are thought to influence the development and progression of inflammatory bowel disease (IBD), but determining generalizable effects of microbiota on IBD etiology requires larger-scale functional analyses. We colonized germ-free mice with intestinal microbiotas from 30 healthy and IBD donors and determined the homeostatic intestinal T cell response to each microbiota. Compared to microbiotas from healthy donors, transfer of IBD microbiotas into germ-free mice increased numbers of intestinal Th17 cells and Th2 cells and decreased numbers of RORγt+ Treg cells. Colonization with IBD microbiotas exacerbated disease in a model where colitis is induced upon transfer of naive T cells into Rag1-/- mice. The proportions of Th17 and RORγt+ Treg cells induced by each microbiota were predictive of human disease status and accounted for disease severity in the Rag1-/- colitis model. Thus, an impact on intestinal Th17 and RORγt+ Treg cell compartments emerges as a unifying feature of IBD microbiotas, suggesting a general mechanism for microbial contribution to IBD pathogenesis.

RevDate: 2019-01-16

Griffith JC, XC Morgan (2019)

Invited Commentary: Improving accessibility of the Human Microbiome Project data through integration with R/Bioconductor.

American journal of epidemiology pii:5288095 [Epub ahead of print].

Alterations in the composition of the microbiota have been implicated in many diseases. The Human Microbiome Project (HMP) provides a comprehensive reference dataset of the "normal" human microbiome of 242 healthy adults at five major body sites. The HMP used both 16S ribosomal RNA gene sequencing and whole-genome metagenomic sequencing to profile the subjects' microbial communities. However, accessing and analyzing the HMP dataset still presents technical and bioinformatic challenges, as researchers must import the microbiome data, integrate phylogenetic trees, and access and merge public and restricted metadata. In this issue, the HMP16SData R/Bioconductor package developed by Schiffer and colleagues (Am J Epidemiol. XXX; XX (XX): XX-XXX) greatly simplifies access to the HMP data by combining 16S taxonomic abundance data, public patient metadata, and phylogenetic trees as a single data object. The authors also provide an interface for users with approved dbGaP projects to easily retrieve and merge the controlled-access HMP metadata. This package has a broad range of appeal to researchers across disciplines and with various levels of expertise in using R and/or other statistical tools. This will translate to improved data accessibility for public health research, with data from healthy individuals serving as a reference for disease-associated studies.

RevDate: 2019-01-16

Schiffer L, Azhar R, Shepherd L, et al (2019)

HMP16SData: Efficient Access to the Human Microbiome Project through Bioconductor.

American journal of epidemiology pii:5288094 [Epub ahead of print].

Phase 1 of the Human Microbiome Project (HMP) investigated 18 body subsites of 239 healthy American adults, to produce the first comprehensive reference for the composition and variation of the "healthy" human microbiome. Publicly-available data sets from amplicon sequencing of two 16S ribosomal RNA variable regions, with extensive controlled-access participant data, provide a reference for ongoing microbiome studies. However, utilization of these data sets can be hindered by the complex bioinformatic steps required to access, import, decrypt, and merge the various components in formats suitable for ecological and statistical analysis. The HMP16SData package provides count data for both 16S ribosomal RNA variable regions, integrated with phylogeny, taxonomy, public participant data, and controlled participant data for authorized researchers, using standard integrative Bioconductor data objects. By removing bioinformatic hurdles of data access and management, HMP16SData enables epidemiologists with only basic R skills to quickly analyze HMP data.

RevDate: 2019-01-16

Sessa L, Reddel S, Manno E, et al (2019)

Distinct gut microbiota profile in ART-treated perinatally HIV-infected patients associated with cardiac and inflammatory biomarkers.

AIDS (London, England) [Epub ahead of print].

OBJECTIVE: Persistent inflammation and higher risk to develop cardiovascular diseases (CVDs) still represent a major complication for HIV-infected patients despite effective antiretroviral therapy (ART). We investigated the correlation between the gut microbiota (GM) profile, markers of inflammation, vascular endothelial activation (VEA) and microbial translocation (MT) in perinatally HIV-infected patients (PHIV) under ART.

DESIGN: Cross-sectional study including sixty-one ART-treated PHIV (age range 3-30 years old) and seventy-one age-matched healthy controls (CTRL). Blood and stool sample were collected at the same time and analyzed for GM composition and plasma biomarkers.

METHODS: GM composition was determined by 16S rRNA targeted-metagenomics. Soluble markers of MT, SI and VEA were quantified by ELISA or Luminex assay. Markers of immune activation were analyzed by flow cytometry on CD4+ and CD8+T-cells.

RESULTS: We identified two distinct GM profiles (group A and B) among PHIV. No different clinical parameters (age, sex, ethnicity, clinical class), dietary and sexual habits were found between the groups. The group A showed a relative dominance of Akkermansia muciniphila (A.muciniphila), whereas GM of group B was characterized by a higher biodiversity. The analysis of soluble markers revealed a significantly higher level of sE-selectin (p = 0.0296), ICAM-1 (p = 0.0028), VCAM-1 (p = 0.0230), IL-6 (p = 0.0247) and sCD14 (p = 0.0142) in group A compared to group B.

CONCLUSIONS: Distinctive GM profiles are differently associated with inflammation, MT and VEA. Future studies are needed in order to understand the role of A.muciniphila and risk to develop CVDs in PHIV.

RevDate: 2019-01-15

Gutiérrez-Barranquero JA, Parages ML, Dobson ADW, et al (2019)

Genome Sequence of Paracoccus sp. JM45, a Bacterial Strain Isolated from a Marine Sponge with a Dual Quorum Sensing Inhibition Activity.

Microbiology resource announcements, 8(2): pii:MRA01496-18.

The draft genome sequence of Paracoccus sp. strain JM45, isolated from a marine sponge harvested off the west coast of Ireland, is reported here. Quorum sensing and quorum sensing inhibition activities have been reported recently for this bacterium, and genomic analysis supports its potential use for novel therapeutic development.

RevDate: 2019-01-12

Feng S, SL McLellan (2019)

Highly specific sewage-derived Bacteroides qPCR assays target sewage polluted waters.

Applied and environmental microbiology pii:AEM.02696-18 [Epub ahead of print].

The identification of sewage contamination in water has primarily relied on detection of the human Bacteroides using markers within the V2 region of the 16S ribosomal RNA (rRNA) gene. Despite establishment of multiple assays that target the HF183 cluster (i.e., Bacteroides dorei) and other Bacteroides organisms (e.g., Bacteroides thetaiotomicron), the potential for more human-associated markers in this genus has not been explored in depth. We examined Bacteroides population structure in sewage and animal hosts across the V4V5 and V6 hypervariable regions. Using near full-length cloned sequences, we identified the sequences in the V4V5 and V6 hypervariable regions that are linked to the HF183 marker in V2 region and found these sequences were present in multiple animals. In addition, the V4V5 and V6 regions contained human fecal marker sequences for organisms that were independent of HF183 cluster. The most abundant Bacteroides in untreated sewage was not human associated but pipe derived. Two TaqMan qPCR assays were developed targeting the V4V5 and V6 regions of this organism. Validation studies using fecal samples from seven animal hosts (n=76) and uncontaminated water samples (n=30) demonstrated their high specificity for sewage. Freshwater Bacteroides were also identified in uncontaminated water samples, demonstrating that measures of total Bacteroides do not reflect fecal pollution. Comparison of two previously described human Bacteroides assays (HB and HF183/BacR287) in municipal wastewater influent and sewage contaminated urban water samples produced identical results, illustrating they target the same organism. Detection of sewage-derived Bacteroides provided an independent measure of sewage-impacted waters.IMPORTANCEBacteroides are major member of the gut microbiota and host-specific organisms within this genus have been used extensively to gain information on pollution sources. This study provides a broad view of the population structure of Bacteroides within sewage to contextualize the well-studied HF183 marker for a human-associated Bacteroides The study also delineates host-specific sequence patterns across multiple hypervariable regions of the 16S rRNA gene to improve our ability to use sequence data to assess water quality. Here, we demonstrate that regions downstream of the HF183 marker are non-specific, but other potential human-associated markers are present. Further, we show the most abundant Bacteroides in sewage is free-living, rather than host associated, and specifically found in sewage. Quantitative PCR assays that target organism specific to sewer pipes offer measures that are independent of the human microbiome for identifying sewage pollution in water.

RevDate: 2019-01-10

Rowan-Nash AD, Korry BJ, Mylonakis E, et al (2019)

Cross-Domain and Viral Interactions in the Microbiome.

Microbiology and molecular biology reviews : MMBR, 83(1): pii:83/1/e00044-18.

SUMMARYThe importance of the microbiome to human health is increasingly recognized and has become a major focus of recent research. However, much of the work has focused on a few aspects, particularly the bacterial component of the microbiome, most frequently in the gastrointestinal tract. Yet humans and other animals can be colonized by a wide array of organisms spanning all domains of life, including bacteria and archaea, unicellular eukaryotes such as fungi, multicellular eukaryotes such as helminths, and viruses. As they share the same host niches, they can compete with, synergize with, and antagonize each other, with potential impacts on their host. Here, we discuss these major groups making up the human microbiome, with a focus on how they interact with each other and their multicellular host.

RevDate: 2019-01-08

Satitsuksanoa P, Jansen K, Głobińska A, et al (2018)

Regulatory Immune Mechanisms in Tolerance to Food Allergy.

Frontiers in immunology, 9:2939.

Oral tolerance can develop after frequent exposure to food allergens. Upon ingestion, food is digested into small protein fragments in the gastrointestinal tract. Small food particles are later absorbed into the human body. Interestingly, some of these ingested food proteins can cause allergic immune responses, which can lead to food allergy. So far it has not been completely elucidated how these proteins become immunogenic and cause food allergies. In contrast, oral tolerance helps to prevent the pathologic reactions against different types of food antigens from animal or plant origin. Tolerance to food is mainly acquired by dendritic cells, epithelial cells in the gut, and the gut microbiome. A subset of CD103+ DCs is capable of inducing T regulatory cells (Treg cells) that express anti-inflammatory cytokines. Anergic T cells also contribute to oral tolerance, by reducing the number of effector cells. Similar to Treg cells, B regulatory cells (Breg cells) suppress effector T cells and contribute to the immune tolerance to food allergens. Furthermore, the human microbiome is an essential mediator in the induction of oral tolerance or food allergy. In this review, we outline the current understanding of regulatory immune mechanisms in oral tolerance. The biological changes reflecting early consequences of immune stimulation with food allergens should provide useful information for the development of novel therapeutic treatments.

RevDate: 2019-01-08

Xiao J, Chen L, Yu Y, et al (2018)

A Phylogeny-Regularized Sparse Regression Model for Predictive Modeling of Microbial Community Data.

Frontiers in microbiology, 9:3112.

Fueled by technological advancement, there has been a surge of human microbiome studies surveying the microbial communities associated with the human body and their links with health and disease. As a complement to the human genome, the human microbiome holds great potential for precision medicine. Efficient predictive models based on microbiome data could be potentially used in various clinical applications such as disease diagnosis, patient stratification and drug response prediction. One important characteristic of the microbial community data is the phylogenetic tree that relates all the microbial taxa based on their evolutionary history. The phylogenetic tree is an informative prior for more efficient prediction since the microbial community changes are usually not randomly distributed on the tree but tend to occur in clades at varying phylogenetic depths (clustered signal). Although community-wide changes are possible for some conditions, it is also likely that the community changes are only associated with a small subset of "marker" taxa (sparse signal). Unfortunately, predictive models of microbial community data taking into account both the sparsity and the tree structure remain under-developed. In this paper, we propose a predictive framework to exploit sparse and clustered microbiome signals using a phylogeny-regularized sparse regression model. Our approach is motivated by evolutionary theory, where a natural correlation structure among microbial taxa exists according to the phylogenetic relationship. A novel phylogeny-based smoothness penalty is proposed to smooth the coefficients of the microbial taxa with respect to the phylogenetic tree. Using simulated and real datasets, we show that our method achieves better prediction performance than competing sparse regression methods for sparse and clustered microbiome signals.

RevDate: 2019-01-03

Osman AEG, JJ Luke (2019)

The Impact of the Fecal Microbiome on Cancer Immunotherapy.

BioDrugs : clinical immunotherapeutics, biopharmaceuticals and gene therapy pii:10.1007/s40259-018-0328-8 [Epub ahead of print].

Recent advances in culture-free methods of studying the human microbiome, coupled with strong bioinformatics tools, have provided new insights on the role of the human microbiome in health and disease. The human gut, in particular, houses a vast number and diverse variety of microbes. A plethora of evidence has demonstrated the significant effects of the gut microbiome on local and systemic immunity. Studies in hematopoietic stem cell transplantation recipients provided early evidence of the involvement of the gut microbiome in the development of graft-versus-host disease and its related mortality. Cancer immunotherapy and checkpoint inhibitors, in particular, harness the power of the host's immune system to fight a range of malignancies. Resistance to immunotherapy and fatal immune-related adverse events both continue to be challenges in the field. The role of the human gut microbiome in affecting the response to immunotherapy was recently uncovered through a series of preclinical and clinical studies. The evidence presented in these studies provides tremendous potential for gut microbes to be used for biomarker development and therapeutic intervention trials.

RevDate: 2018-12-28

van Dijkhuizen EHP, Del Chierico F, Malattia C, et al (2018)

Microbiome analytics of the gut microbiota in juvenile idiopathic arthritis patients: an observational, longitudinal cohort study.

Arthritis & rheumatology (Hoboken, N.J.) [Epub ahead of print].

OBJECTIVES: To assess the composition of gut microbiota in Italian and Dutch juvenile idiopathic arthritis (JIA) patients at baseline, in inactive disease and persistent activity, compared to healthy controls.

METHODS: In a prospective, multicenter, observational cohort study, fecal samples were collected of 78 Italian and 21 Dutch treatment-naïve JIA patients at baseline with less than 6 months disease duration and compared to 107 geography-matched samples of healthy children. Furthermore, 44 follow up samples in inactive disease and 25 in persistent activity were analyzed. Gut microbiota composition was determined by 16S rRNA-based-metagenomics. The α- and β-diversity were computed, and log-ratios of relative abundance were compared between patients and healthy controls using random forest models and logistic regression.

RESULTS: Italian baseline samples showed reduced richness compared to healthy controls (p <0.001). Random forest distinguished Italian baseline samples from controls and suggested differences between Dutch samples and controls (area under the curve >0.99 and 0.71, respectively). Mainly the Operational Taxonomic Units (OTUs) Erysipelotrichaceae (increased in patients), Allobaculum (decreased) and Faecalibacterium prausnitzii (increased) showed different relative abundance in Italian baseline samples compared to controls after controlling for multiple comparisons. Some OTUs differed between Dutch samples and healthy controls, but no evidence remained after controlling for multiple comparisons. No differences were found in paired analysis between Italian baseline and inactive disease samples.

CONCLUSIONS: We found evidence for dysbiosis in JIA patients. Only patient/control status, age and geographical origin appeared to be drivers of the microbiota profiles, regardless of disease activity stage, inflammation and autoimmunity markers. This article is protected by copyright. All rights reserved.

RevDate: 2018-12-27

Wei F, Wu Q, Hu Y, et al (2018)

Conservation metagenomics: a new branch of conservation biology.

Science China. Life sciences pii:10.1007/s11427-018-9423-3 [Epub ahead of print].

Multifaceted approaches are required to monitor wildlife populations and improve conservation efforts. In the last decade, increasing evidence suggests that metagenomic analysis offers valuable perspectives and tools for identifying microbial communities and functions. It has become clear that gut microbiome plays a critical role in health, nutrition, and physiology of wildlife, including numerous endangered animals in the wild and in captivity. In this review, we first introduce the human microbiome and metagenomics, highlighting the importance of microbiome for host fitness. Then, for the first time, we propose the concept of conservation metagenomics, an emerging subdiscipline of conservation biology, which aims to understand the roles of the microbiota in evolution and conservation of endangered animals. We define what conservation metagenomics is along with current approaches, main scientific issues and significant implications in the study of host evolution, physiology, nutrition, ecology and conservation. We also discuss future research directions of conservation metagenomics. Although there is still a long way to go, conservation metagenomics has already shown a significant potential for improving the conservation and management of wildlife.

RevDate: 2018-12-25

Zhang J, Zhang F, Zhao C, et al (2018)

Dysbiosis of the gut microbiome is associated with thyroid cancer and thyroid nodules and correlated with clinical index of thyroid function.

Endocrine pii:10.1007/s12020-018-1831-x [Epub ahead of print].

PURPOSE: Thyroid cancer and thyroid nodules are the most prevalent form of thyroid endocrine disorder. The balance of gut microbiome is highly crucial for a healthy human body, especially for the immune and endocrine system. However, the relationship between gut microbiome and the thyroid endocrine disorders such as thyroid cancer and thyroid nodules has not been reported yet.

METHODS: A cohort of 74 patients was recruited for this study. Among them, 20 patients had thyroid cancer, 18 patients had thyroid nodules, and 36 were matched healthy controls. Gut microbiome composition was analyzed by 16S rRNA (16S ribosomal RNA) gene-based sequencing protocol.

RESULTS: We compared the gut microbiome results of 74 subjects and established the correlation between gut microbiome and thyroid endocrine function for both thyroid cancer and thyroid nodules. The results inferred that alpha and beta diversity were different for patients with thyroid tumor than the healthy controls (p < 0.01). In comparison to healthy controls, the relative abundance of Neisseria (p < 0.001) and Streptococcus (p < 0.001) was significantly higher for thyroid cancer and thyroid nodules. Butyricimonas (p < 0.001) and Lactobacillus (p < 0.001) displayed notably lower relative abundance for thyroid cancer and thyroid nodules, respectively. It was also found that the clinical indexes were correlated with gut microbiome.

CONCLUSION: Our results indicate that both thyroid cancer and thyroid nodules are associated with the composition of gut microbiome. These results may support further clinical diagnosis to a great extent and help in developing potential probiotics to facilitate the treatment of thyroid cancer and thyroid nodules.

RevDate: 2018-12-22

Nobili V, Mosca A, Alterio T, et al (2018)

Fighting Fatty Liver Diseases with Nutritional Interventions, Probiotics, Symbiotics, and Fecal Microbiota Transplantation (FMT).

Advances in experimental medicine and biology [Epub ahead of print].

Pediatric obesity is rising worldwide leading the worrying phenomenon of nonalcoholic fatty liver disease (NAFLD) to shift into one of the most frequent causes of chronic liver illness in childhood. Occurrence of NAFLD depends on several factors such as the geographical area and the diagnostic modalities used; overall it ranges between 3% and 10% of pediatric population, increasing up to 70% in patients with metabolic comorbidities (Manco M, Bottazzo G, DeVito R et al, J Am Coll Nutr 27:667-676, 2008).Recent findings have related the intestinal microbiota to a plethora of pathological conditions, including type 2 diabetes (T2D), obesity, and nonalcoholic steatohepatitis (NASH). One of the emerging areas of the study is the link between liver diseases and gut microbiome, which has added new information to the understanding of the so-called gut-liver axis.In order to address the role of gut microbiome in NAFLD onset and progression, it is necessary to "decipher" operational codes for microbiome investigation within the context of advanced laboratory medicine to capture microbiome features and, hence, to address the function of the intestinal microbiome within the gut microbiota-liver axis.Results of these investigations have allowed the beginning of implementing the usage of probiotics and symbiotics in the medical approach of obesity and NAFLD in adults and children. Several randomized clinical trials (RCTs) have been already published on fecal microbiota transplantation (FMT), T2D, NASH, and inflammatory bowel disease (IBD).This review proposes to describe the current state of knowledge on the ways fatty liver diseases can be addressed with nutritional interventions, probiotics, symbiotics, and FMT.

RevDate: 2018-12-22

Stubbendieck RM, May DS, Chevrette MG, et al (2018)

Competition among nasal bacteria suggests a role for siderophore-mediated interactions in shaping the human nasal microbiota.

Applied and environmental microbiology pii:AEM.02406-18 [Epub ahead of print].

Resources available in the human nasal cavity are limited. Therefore, to successfully colonize the nasal cavity, bacteria must compete for scarce nutrients. Competition may occur directly through interference (e.g., antibiotics) or indirectly by nutrient sequestration. To investigate the nature of nasal bacterial competition, we performed co-culture inhibition assays between nasal Actinobacteria and Staphylococcus spp. We found that coagulase-negative staphylococci (CoNS) isolates were sensitive to growth inhibition by Actinobacteria but Staphylococcus aureus isolates were resistant to inhibition. Among Actinobacteria, we observed that Corynebacterium spp. were variable in their ability to inhibit CoNS. We sequenced the genomes of ten Corynebacterium spp. isolates, including three Corynebacterium propinquum that strongly inhibited CoNS and seven other Corynebacterium spp. isolates that only weakly inhibited CoNS Using a comparative genomics approach, we found that the C. propinquum genomes were enriched in genes for iron acquisition and encoded a biosynthetic gene cluster (BGC) for siderophore production, absent in the non-inhibitory Corynebacterium spp. genomes. Using a chromeazurol S assay, we confirmed that C. propinquum produced siderophores. We demonstrated that iron supplementation rescued CoNS from inhibition by C. propinquum, suggesting that inhibition was due to iron restriction through siderophore production. Through comparative metabolomics and molecular networking, we identified the siderophore produced by C. propinquum as dehydroxynocardamine. Finally, we confirmed that the dehydroxynocardamine BGC is expressed in vivo by analyzing human nasal metatranscriptomes from the NIH Human Microbiome Project. Together, our results suggest that bacteria produce siderophores to compete for limited available iron in the nasal cavity and improve their fitness.IMPORTANCE Within the nasal cavity, interference competition through antimicrobial production is prevalent. For instance, nasal Staphylococcus spp. strains can inhibit the growth of other bacteria through the production of nonribosomal peptides and ribosomally synthesized and post-translationally modified peptides. In contrast, bacteria engaging in exploitation competition modify the external environment to prevent competitors from growing, usually by depleting access to essential nutrients. As the nasal cavity is a nutrient limited environment, we hypothesized that exploitation competition occurs in this system. We determined that Corynebacterium propinquum produces an iron-chelating siderophore and this iron-sequestering molecule correlates with the ability to inhibit the growth of coagulase-negative staphylococci. Further, we found that the genes required for siderophore production are expressed in vivo Thus, though siderophore production by bacteria is often considered a virulence trait, our work indicates that bacteria may produce siderophores to compete for limited iron in the human nasal cavity.

RevDate: 2018-12-22

Yang AJ, Marito S, Yang JJ, et al (2018)

A Microtube Array Membrane (MTAM) Encapsulated Live Fermenting Staphylococcus epidermidis as a Skin Probiotic Patch against Cutibacterium acnes.

International journal of molecular sciences, 20(1): pii:ijms20010014.

Antibiotics without selectivity for acne treatment may destroy the beneficial microbes in the human microbiome that helps to fight Cutibacterium acnes (C. acnes), a bacterium associated with inflammatory acne vulgaris. Probiotic treatment by direct application of live Staphylococcus epidermidis (S. epidermidis) onto the open acne lesions may run the risk of bloodstream infections. Here, we fabricated the polysulfone microtube array membranes (PSF MTAM) to encapsulate probiotic S.epidermidis. We demonstrate that the application of the encapsulation of S.epidermidis in PSF MTAM enhanced the glycerol fermentation activities of S. epidermidis. To mimic the granulomatous type of acne inflammatory acne vulgaris, the ears of mice were injected intradermally with C.acnes to induce the secretion of macrophage inflammatory protein-2 (MIP-2), a murine counterpart of human interleukin (IL)-8. The C. acnes-injected mouse ears were covered with a PST MTAM encapsulated with or without S.epidermidis in the presence of glycerol. The application of S.epidermidis-encapsulated PST MTAM plus glycerol onto the C.acnes-injected mouse ears considerably reduced the growth of C. acnes and the production of MIP-2. Furthermore, no S. epidermidis leaked from PSF MTAM into mouse skin. The S. epidermidis-encapsulated PST MTAM functions as a probiotic acne patch.

RevDate: 2018-12-21

Coryell M, McAlpine M, Pinkham NV, et al (2018)

The gut microbiome is required for full protection against acute arsenic toxicity in mouse models.

Nature communications, 9(1):5424 pii:10.1038/s41467-018-07803-9.

Arsenic poisons an estimated 200 million people worldwide through contaminated food and drinking water. Confusingly, the gut microbiome has been suggested to both mitigate and exacerbate arsenic toxicity. Here, we show that the microbiome protects mice from arsenic-induced mortality. Both antibiotic-treated and germ-free mice excrete less arsenic in stool and accumulate more arsenic in organs compared to control mice. Mice lacking the primary arsenic detoxification enzyme (As3mt) are hypersensitive to arsenic after antibiotic treatment or when derived germ-free, compared to wild-type and/or conventional counterparts. Human microbiome (stool) transplants protect germ-free As3mt-KO mice from arsenic-induced mortality, but protection depends on microbiome stability and the presence of specific bacteria, including Faecalibacterium. Our results demonstrate that both a functional As3mt and specific microbiome members are required for protection against acute arsenic toxicity in mouse models. We anticipate that the gut microbiome will become an important explanatory factor of disease (arsenicosis) penetrance in humans, and a novel target for prevention and treatment strategies.

RevDate: 2018-12-21

Altomare A, Putignani L, Del Chierico F, et al (2018)

Gut mucosal-associated microbiota better discloses Inflammatory Bowel Disease differential patterns than faecal microbiota.

Digestive and liver disease : official journal of the Italian Society of Gastroenterology and the Italian Association for the Study of the Liver pii:S1590-8658(18)31260-X [Epub ahead of print].

BACKGROUND: Growing evidence supports the potential role of intestinal microbiota in the pathophysiology of Inflammatory Bowel Diseases (IBD) even if the literature does not reveal uniform alterations. The aim of the study was to evaluate the mucosal (MM) and faecal microbiota (FM) composition in a cohort of IBD patients compared to healthy controls (CTRLs).

METHODS: Faecal and mucosal samples were collected from 14 IBD patients and 11 CTRLs. The V1-V3 region of 16S rRNA locus was amplified on a 454-Junior Genome Sequencer. Reads were grouped into operational taxonomic units (OTUs) at a sequence similarity level of 97% for taxonomic assignment, and aligned for OTUs matching against Greengenes database.

RESULTS: Irrespective of disease localization and activity, in the MM of IBD patients a statistically significant increase of Proteobacteria (especially Enterobacteriaceae, Acidaminococcus, Veillonella dispar) and decrease of Firmicutes (especially Roseburia and Faecalibacterium prausnitzii) and Actinobacteria was found compared to CTRLs. In the colon district some specific bacterial biomarkers were identified: Enterobacteriaceae for IBD stools, Bacteroides for IBD biopsies, Mogibacteriaceae, Ruminococcaceae and Prevotella for CTRL stools, Ruminococcaceae for CTRL biopsies.

CONCLUSIONS: The profiles of FM were more similar to CTRLs, suggesting that microbiota adhering to the gut mucosa better discriminates patients from controls, with the identification of some interesting biomarkers.

RevDate: 2018-12-21

Sánchez-Ponce Y, Varela-Fascinetto G, Romo-Vázquez JC, et al (2018)

Simultaneous Detection of Beta and Gamma Human Herpesviruses by Multiplex qPCR Reveals Simple Infection and Coinfection Episodes Increasing Risk for Graft Rejection in Solid Organ Transplantation.

Viruses, 10(12): pii:v10120730.

Herpesviruses are common components of the human microbiome that become clinically relevant when a competent immunosurveillance is compromised, such as in transplantation. Members of the beta and gamma subfamilies are associated with a wide diversity of pathologies, including end-organ disease and cancer. In this study, we developed a multiplex qPCR technique with high specificity, sensitivity, efficiency and predictability that allowed the simultaneous detection and quantification of beta and gamma human herpesviruses. The technique was tested in a cohort of 34 kidney- or liver-transplanted pediatric patients followed up for up to 12 months post-transplant. Viral load was determined in 495 leukocyte-plasma paired samples collected bi-weekly or monthly. Human herpesvirus (HHV) 7 was the herpesvirus most frequently found in positive samples (39%), followed by Epstein-Barr virus (EBV) (20%). Also, EBV and HHV7 were present in the majority of coinfection episodes (62%). The share of positive samples exclusively detected either in leukocytes or plasma was 85%, suggesting that these herpesviruses tended to take a latent or lytic path in an exclusive manner. Infection by human cytomegalovirus (HCMV) and HHV6, as well as coinfection by EBV/HHV7 and EBV/HHV6/HHV7, were associated with graft rejection (RR = 40.33 (p = 0.0013), 5.60 (p = 0.03), 5.60 (p = 0.03) and 17.64 (p = 0.0003), respectively). The routine monitoring of beta and gamma herpesviruses should be mandatory in transplant centers to implement preventive strategies.

RevDate: 2018-12-19

Proal A, T Marshall (2018)

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome in the Era of the Human Microbiome: Persistent Pathogens Drive Chronic Symptoms by Interfering With Host Metabolism, Gene Expression, and Immunity.

Frontiers in pediatrics, 6:373.

The illness ME/CFS has been repeatedly tied to infectious agents such as Epstein Barr Virus. Expanding research on the human microbiome now allows ME/CFS-associated pathogens to be studied as interacting members of human microbiome communities. Humans harbor these vast ecosystems of bacteria, viruses and fungi in nearly all tissue and blood. Most well-studied inflammatory conditions are tied to dysbiosis or imbalance of the human microbiome. While gut microbiome dysbiosis has been identified in ME/CFS, microbes and viruses outside the gut can also contribute to the illness. Pathobionts, and their associated proteins/metabolites, often control human metabolism and gene expression in a manner that pushes the body toward a state of illness. Intracellular pathogens, including many associated with ME/CFS, drive microbiome dysbiosis by directly interfering with human transcription, translation, and DNA repair processes. Molecular mimicry between host and pathogen proteins/metabolites further complicates this interference. Other human pathogens disable mitochondria or dysregulate host nervous system signaling. Antibodies and/or clonal T cells identified in patients with ME/CFS are likely activated in response to these persistent microbiome pathogens. Different human pathogens have evolved similar survival mechanisms to disable the host immune response and host metabolic pathways. The metabolic dysfunction driven by these organisms can result in similar clusters of inflammatory symptoms. ME/CFS may be driven by this pathogen-induced dysfunction, with the nature of dysbiosis and symptom presentation varying based on a patient's unique infectious and environmental history. Under such conditions, patients would benefit from treatments that support the human immune system in an effort to reverse the infectious disease process.

RevDate: 2018-12-18

Tedijanto C, Olesen SW, Grad YH, et al (2018)

Estimating the proportion of bystander selection for antibiotic resistance among potentially pathogenic bacterial flora.

Proceedings of the National Academy of Sciences of the United States of America pii:1810840115 [Epub ahead of print].

Bystander selection-the selective pressure for resistance exerted by antibiotics on microbes that are not the target pathogen of treatment-is critical to understanding the total impact of broad-spectrum antibiotic use on pathogenic bacterial species that are often carried asymptomatically. However, to our knowledge, this effect has never been quantified. We quantify bystander selection for resistance for a range of clinically relevant antibiotic-species pairs as the proportion of all antibiotic exposures received by a species for conditions in which that species was not the causative pathogen ("proportion of bystander exposures"). Data sources include the 2010-2011 National Ambulatory Medical Care Survey and National Hospital Ambulatory Medical Care Survey, the Human Microbiome Project, and additional carriage and etiological data from existing literature. For outpatient prescribing in the United States, we find that this proportion over all included antibiotic classes is over 80% for eight of nine organisms of interest. Low proportions of bystander exposure are often associated with infrequent bacterial carriage or concentrated prescribing of a particular antibiotic for conditions caused by the species of interest. Applying our results, we roughly estimate that pneumococcal conjugate vaccination programs result in nearly the same proportional reduction in total antibiotic exposures of Streptococcus pneumoniae, Staphylococcus aureus, and Escherichia coli, despite the latter two organisms not being targeted by the vaccine. These results underscore the importance of considering antibiotic exposures of bystanders, in addition to the target pathogen, in measuring the impact of antibiotic resistance interventions.

RevDate: 2018-12-18

Relman DA, M Lipsitch (2018)

Microbiome as a tool and a target in the effort to address antimicrobial resistance.

Proceedings of the National Academy of Sciences of the United States of America pii:1717163115 [Epub ahead of print].

Reciprocal, intimate relationships between the human microbiome and the host immune system are shaped by past microbial encounters and prepare the host for future ones. Antibiotics and other antimicrobials leave their mark on both the microbiome and host immunity. Antimicrobials alter the structure of the microbiota, expand the host-specific pool of antimicrobial-resistance genes and organisms, degrade the protective effects of the microbiota against invasion by pathogens, and may impair vaccine efficacy. Through these effects on the microbiome they may affect immune responses. Vaccines that exert protective or therapeutic effects against pathogens may reduce the use of antimicrobials, the development and spread of antimicrobial resistance, and the harmful impacts of these drugs on the microbiome. Other strategies involving manipulation of the microbiome to deplete antibiotic-resistant organisms or to enhance immune responses to vaccines may prove valuable in addressing antimicrobial resistance as well. This article describes the intersections of immunity, microbiome and antimicrobial exposure, and the use of vaccines and other alternative strategies for the control and management of antimicrobial resistance.

RevDate: 2018-12-15

Romani L, Pane S, Severini C, et al (2018)

Challenging diagnosis of congenital malaria in non-endemic areas.

Malaria journal, 17(1):470 pii:10.1186/s12936-018-2614-9.

BACKGROUND: Congenital malaria is usually defined as the detection of asexual forms of Plasmodium spp. in a blood sample of a neonate during perinatal age if there is no possibility of postpartum infection by a mosquito bite. The incidence of congenital malaria is highly variable and seems related to several factors, such as different diagnostic methods for Plasmodium spp. detection, and area in which the epidemiologic analyses are performed. In non-endemic countries, cases of congenital malaria are rare. Hereby, a case of a congenital malaria in an HIV exposed child is reported.

CASE PRESENTATION: A 2-month-old male child was admitted to Bambino Gesù Children's Hospital due to anaemia and exposure to HIV. He was born prematurely in Italy by cesarean section at 34 weeks' gestation after a bicorial, biamniotic pregnancy by a migrant woman from Nigeria. He was the first of non-identical twins. Combined with anaemia, spleen and liver enlargement was noted, malaria was hypothesized. Malaria laboratory panel was performed on the newborn, mother and other twin blood samples, as follows: (i) malaria rapid diagnostic test (RDT); (ii) Giemsa-stained thick and thin blood smears for Plasmodium spp. identification and parasitaemia titration; (iii) molecular screening and typing of Plasmodium spp. by multiplex qualitative PCR assay based on 18S rRNA gene. Genotyping of Plasmodium falciparum isolates from mother and child was performed by neutral microsatellite and highly polymorphic marker amplification.

CONCLUSIONS: The maternal RDT sample was negative, while the infant RDT was positive; in both cases microscopy of blood smears and PCR showed infection with P. falciparum. Two of the genotypic molecular markers displayed different allelic variants between the two samples. This difference could imply infection multiplicity of the mother during the pregnancy, possibly harbouring more than one isolate, only one of them being transmitted to the newborn while the other persisting in the mother's blood. Because of the increasing number of pregnant women coming from endemic areas for malaria, an accurate anamnesis of infant's mother, and the inclusion of Plasmodium spp. research into TORCH screenings for mother-infant pair at birth, aiming at reducing morbidity and mortality associated to the disease might be suitable.

RevDate: 2018-12-14

D'Argenio V (2018)

The Prenatal Microbiome: A New Player for Human Health.

High-throughput, 7(4): pii:ht7040038.

The last few years have featured an increasing interest in the study of the human microbiome and its correlations with health status. Indeed, technological advances have allowed the study of microbial communities to reach a previously unthinkable sensitivity, showing the presence of microbes also in environments usually considered as sterile. In this scenario, microbial communities have been described in the amniotic fluid, the umbilical blood cord, and the placenta, denying a dogma of reproductive medicine that considers the uterus like a sterile womb. This prenatal microbiome may play a role not only in fetal development but also in the predisposition to diseases that may develop later in life, and also in adulthood. Thus, the aim of this review is to report the current knowledge regarding the prenatal microbiome composition, its association with pathological processes, and the future perspectives regarding its manipulation for healthy status promotion and maintenance.

RevDate: 2018-12-07

Yang J, Mu X, Wang Y, et al (2018)

Dysbiosis of the Salivary Microbiome Is Associated With Non-smoking Female Lung Cancer and Correlated With Immunocytochemistry Markers.

Frontiers in oncology, 8:520.

Background: Association between oral bacteria and increased risk of lung cancer have been reported in several previous studies, however, the potential association between salivary microbiome and lung cancer in non-smoking women have not been evaluated. There is also no report on the relationship between immunocytochemistry markers and salivary microbiota. Method: In this study, we assessed the salivary microbiome of 75 non-smoking female lung cancer patients and 172 matched healthy individuals using 16S rRNA gene amplicon sequencing. We also calculated the Spearman's rank correlation coefficient between salivary microbiota and three immunohistochemical markers (TTF-1, Napsin A and CK7). Result: We analyzed the salivary microbiota of 247 subjects and found that non-smoking female lung cancer patients exhibited oral microbial dysbiosis. There was significantly lower microbial diversity and richness in lung cancer patients when compared to the control group (Shannon index, P < 0.01; Ace index, P < 0.0001). Based on the analysis of similarities, the composition of the microbiota in lung cancer patients also differed from that of the control group (r = 0.454, P < 0.001, unweighted UniFrac; r = 0.113, P < 0.01, weighted UniFrac). The bacterial genera Sphingomonas (P < 0.05) and Blastomonas (P < 0.0001) were relatively higher in non-smoking female lung cancer patients, whereas Acinetobacter (P < 0.001) and Streptococcus (P < 0.01) were higher in controls. Based on Spearman's correlation analysis, a significantly positive correlation can be observed between CK7 and Enterobacteriaceae (r = 0.223, P < 0.05). At the same time, Napsin A was positively associated with genera Blastomonas (r = 0.251, P < 0.05). TTF-1 exhibited a significantly positive correlation with Enterobacteriaceae (r = 0.262, P < 0.05). Functional analysis from inferred metagenomes indicated that oral microbiome in non-smoking female lung cancer patients were related to cancer pathways, p53 signaling pathway, apoptosis and tuberculosis. Conclusions: The study identified distinct salivary microbiome profiles in non-smoking female lung cancer patients, revealed potential correlations between salivary microbiome and immunocytochemistry markers used in clinical diagnostics, and provided proof that salivary microbiota can be an informative source for discovering non-invasive lung cancer biomarkers.

RevDate: 2018-12-11

Escapa IF, Chen T, Huang Y, et al (2018)

New Insights into Human Nostril Microbiome from the Expanded Human Oral Microbiome Database (eHOMD): a Resource for the Microbiome of the Human Aerodigestive Tract.

mSystems, 3(6): pii:mSystems00187-18.

The expanded Human Oral Microbiome Database (eHOMD) is a comprehensive microbiome database for sites along the human aerodigestive tract that revealed new insights into the nostril microbiome. The eHOMD provides well-curated 16S rRNA gene reference sequences linked to available genomes and enables assignment of species-level taxonomy to most next-generation sequences derived from diverse aerodigestive tract sites, including the nasal passages, sinuses, throat, esophagus, and mouth. Using minimum entropy decomposition coupled with the RDP Classifier and our eHOMD V1-V3 training set, we reanalyzed 16S rRNA V1-V3 sequences from the nostrils of 210 Human Microbiome Project participants at the species level, revealing four key insights. First, we discovered that Lawsonella clevelandensis, a recently named bacterium, and Neisseriaceae [G-1] HMT-174, a previously unrecognized bacterium, are common in adult nostrils. Second, just 19 species accounted for 90% of the total sequences from all participants. Third, 1 of these 19 species belonged to a currently uncultivated genus. Fourth, for 94% of the participants, 2 to 10 species constituted 90% of their sequences, indicating that the nostril microbiome may be represented by limited consortia. These insights highlight the strengths of the nostril microbiome as a model system for studying interspecies interactions and microbiome function. Also, in this cohort, three common nasal species (Dolosigranulum pigrum and two Corynebacterium species) showed positive differential abundance when the pathobiont Staphylococcus aureus was absent, generating hypotheses regarding colonization resistance. By facilitating species-level taxonomic assignment to microbes from the human aerodigestive tract, the eHOMD is a vital resource enhancing clinical relevance of microbiome studies. IMPORTANCE The eHOMD (http://www.ehomd.org) is a valuable resource for researchers, from basic to clinical, who study the microbiomes and the individual microbes in body sites in the human aerodigestive tract, which includes the nasal passages, sinuses, throat, esophagus, and mouth, and the lower respiratory tract, in health and disease. The eHOMD is an actively curated, web-based, open-access resource. eHOMD provides the following: (i) species-level taxonomy based on grouping 16S rRNA gene sequences at 98.5% identity, (ii) a systematic naming scheme for unnamed and/or uncultivated microbial taxa, (iii) reference genomes to facilitate metagenomic, metatranscriptomic, and proteomic studies and (iv) convenient cross-links to other databases (e.g., PubMed and Entrez). By facilitating the assignment of species names to sequences, the eHOMD is a vital resource for enhancing the clinical relevance of 16S rRNA gene-based microbiome studies, as well as metagenomic studies.

RevDate: 2018-12-11

Lim MY, Cho Y, M Rho (2018)

Diverse Distribution of Resistomes in the Human and Environmental Microbiomes.

Current genomics, 19(8):701-711.

The routine therapeutic use of antibiotics has caused resistance genes to be disseminated across microbial populations. In particular, bacterial strains having antibiotic resistance genes are frequently observed in the human microbiome. Moreover, multidrug-resistant pathogens are now widely spread, threatening public health. Such genes are transferred and spread among bacteria even in different environments. Advances in high throughput sequencing technology and computational algorithms have accelerated investigation into antibiotic resistance genes of bacteria. Such studies have revealed that the antibiotic resistance genes are located close to the mobility-associated genes, which promotes their dissemination. An increasing level of information on genomic sequences of resistome should expedite research on drug-resistance in our body and environment, thereby contributing to the development of public health policy. In this review, the high prevalence of antibiotic resistance genes and their exchange in the human and environmental microbiome is discussed with respect to the genomic contents. The relationships among diverse resistomes, related bacterial species, and the antibiotics are reviewed. In addition, recent advances in bioinformatics approaches to investigate such relationships are discussed.

RevDate: 2018-12-11

Ben Y, Fu C, Hu M, et al (2018)

Human health risk assessment of antibiotic resistance associated with antibiotic residues in the environment: A review.

Environmental research, 169:483-493 pii:S0013-9351(18)30429-8 [Epub ahead of print].

The extensive use of antibiotics leading to the rapid spread of antibiotic resistance poses high health risks to humans, but to date there is still lack of a quantitative model to properly assess the risks. Concerns over the health risk of antibiotic residues in the environment are mainly (1) the potential hazard of ingested antibiotic residues in the environment altering the human microbiome and promoting emergence and selection for bacteria resistance inhabiting the human body, and (2) the potential hazard of creating a selection pressure on environmental microbiome and leading to reservoirs of antibiotic resistance in the environment. We provide a holistic view of health risk assessment of antibiotic resistance associated with antibiotic residues in the environment in contrast with that of the antibiotic resistant bacteria and discuss the main knowledge gaps and the future research that should be prioritized to achieve the quantitative risk assessment. We examined and summarized the available data and information on the four core elements of antibiotic resistance associated with antibiotic residues in the environment: hazard identification, exposure assessment, dose-response assessment, and risk characterization. The data required to characterize the risks of antibiotic residues in the environment is severely limited. The main future research needs have been identified to enable better assessments of antibiotic resistance associated with antibiotic residues in the environment: (1) establishment of a standardized monitoring guide of antibiotic residues and antibiotic resistance in the environment, (2) derivation of the relationship between antibiotic levels and pathogenic antibiotic-resistance development in different settings, and (3) establishment of the dose-response relationship between pathogenic antibiotic resistant bacteria and various infection diseases. After identification of key risk determinant parameters, we propose a conceptual framework of human health risk assessments of antibiotic residues in the environment. CAPSULE: A holistic view of human health risk assessment of antibiotic residues in the environment was provided.

RevDate: 2018-12-11

Robertson RC, Manges AR, Finlay BB, et al (2018)

The Human Microbiome and Child Growth - First 1000 Days and Beyond.

Trends in microbiology pii:S0966-842X(18)30204-X [Epub ahead of print].

The assembly of microbial communities within the gastrointestinal tract during early life plays a critical role in immune, endocrine, metabolic, and other host developmental pathways. Environmental insults during this period, such as food insecurity and infections, can disrupt this optimal microbial succession, which may contribute to lifelong and intergenerational deficits in growth and development. Here, we review the human microbiome in the first 1000 days - referring to the period from conception to 2 years of age - and using a developmental model, we examine the role of early microbial succession in growth and development. We propose that an 'undernourished' microbiome is intergenerational, thereby perpetuating growth impairments into successive generations. We also identify and discuss the intertwining host-microbe-environment interactions occurring prenatally and during early infancy, which may impair the trajectories of healthy growth and development, and explore their potential as novel microbial targets for intervention.

RevDate: 2018-12-11

Blaser MJ (2018)

Our missing microbes: Short-term antibiotic courses have long-term consequences.

Cleveland Clinic journal of medicine, 85(12):928-930.

RevDate: 2018-12-06

Jeżewska-Frąckowiak J, Seroczyńska K, Banaszczyk J, et al (2018)

The promises and risks of probiotic Bacillus species.

Acta biochimica Polonica pii:2652 [Epub ahead of print].

Supplementing the human microbiome with probiotic microorganisms is a proposed solution for civilization syndromes such as dysbiosis and gastrointestinal tract (GIT) disorders. Bimodal probiotic strains of the Bacillus genus constitute the microbiota of the human environment, and are typically found in soil, water, a number of non-dairy fermented foods, as well as in human and animal GIT. Probiotic Bacillus sp. are Gram positive rods, with the ability of sporulation to survive environmental stress and preparation conditions. In vitro models of the human stomach and human studies with probiotic Bacillus reveal the mechanisms of its life cycle and sporulation. The Bacillus sp. probiotic biofilm introduces biochemical effects such as antimicrobial and enzymatic activity, thus contributing to protection from GIT and other infections. Despite the beneficial activity of Bacillus strains belonging to the safety group 1, a number of strains can pose a substantial health risk, carrying genes for various toxins or antibiotic resistance. Commercially available Bacillus probiotic preparations include strains from the subtilis and other closely related phylogenetic clades. Those intended for oral administration in humans, often encapsulated with appropriate supporting materials, still tend to be mislabeled or poorly characterized. Bacillus sp. MALDI-TOF analysis, combined with sequencing of characteristic 16S rRNA or enzyme coding genes, may provide accurate identification. A promising future application of the probiotic Bacillus sp. might be the microflora biocontrol in the human body and the closest human environment. Environmental probiotic Bacillus species display the potential to support human microflora, however controversies regarding the safety of certain strains is a key factor in their still limited application.

RevDate: 2018-12-06

Vernocchi P, Del Chierico F, Russo A, et al (2018)

Gut microbiota signatures in cystic fibrosis: Loss of host CFTR function drives the microbiota enterophenotype.

PloS one, 13(12):e0208171 pii:PONE-D-17-43072.

BACKGROUND: Cystic fibrosis (CF) is a disorder affecting the respiratory, digestive, reproductive systems and sweat glands. This lethal hereditary disease has known or suspected links to the dysbiosis gut microbiota. High-throughput meta-omics-based approaches may assist in unveiling this complex network of symbiosis modifications.

OBJECTIVES: The aim of this study was to provide a predictive and functional model of the gut microbiota enterophenotype of pediatric patients affected by CF under clinical stability.

METHODS: Thirty-one fecal samples were collected from CF patients and healthy children (HC) (age range, 1-6 years) and analysed using targeted-metagenomics and metabolomics to characterize the ecology and metabolism of CF-linked gut microbiota. The multidimensional data were low fused and processed by chemometric classification analysis.

RESULTS: The fused metagenomics and metabolomics based gut microbiota profile was characterized by a high abundance of Propionibacterium, Staphylococcus and Clostridiaceae, including Clostridium difficile, and a low abundance of Eggerthella, Eubacterium, Ruminococcus, Dorea, Faecalibacterium prausnitzii, and Lachnospiraceae, associated with overexpression of 4-aminobutyrate (GABA), choline, ethanol, propylbutyrate, and pyridine and low levels of sarcosine, 4-methylphenol, uracil, glucose, acetate, phenol, benzaldehyde, and methylacetate. The CF gut microbiota pattern revealed an enterophenotype intrinsically linked to disease, regardless of age, and with dysbiosis uninduced by reduced pancreatic function and only partially related to oral antibiotic administration or lung colonization/infection.

CONCLUSIONS: All together, the results obtained suggest that the gut microbiota enterophenotypes of CF, together with endogenous and bacterial CF biomarkers, are direct expression of functional alterations at the intestinal level. Hence, it's possible to infer that CFTR impairment causes the gut ecosystem imbalance.This new understanding of CF host-gut microbiota interactions may be helpful to rationalize novel clinical interventions to improve the affected children's nutritional status and intestinal function.

RevDate: 2018-12-06

Slobodin G, Rosner I, A Kessel (2018)

Dendritic cells in the pathogenesis of ankylosing spondylitis and axial spondyloarthritis.

Clinical rheumatology pii:10.1007/s10067-018-4388-4 [Epub ahead of print].

The interaction of dendritic cells (DCs) with the human microbiome, with distorted handling of the microbiota or its products via the direct effect of HLA B27, probably represents the initial element in the chain of events leading to the development of clinical axial spondyloarthritis. The mechanism of disease extension onto the skeleton and other tissues involved, such as uvea, may also involve migratory DCs. Finally, the role of DCs in the initiation of the inflammatory tissue response with activation of the IL-17 axis has been demonstrated. Further, some initial data suggests the possible connection of DCs with disease-related new bone formation.

RevDate: 2018-12-03

Lai PS, DC Christiani (2018)

Impact of occupational exposure on human microbiota.

Current opinion in allergy and clinical immunology [Epub ahead of print].

PURPOSE OF REVIEW: Recent evidence suggests that environmental exposures change the adult human microbiome. Here, we review recent evidence on the impact of the work microbiome and work-related chemical, metal and particulate exposures on the human microbiome.

RECENT FINDINGS: Prior literature on occupational microbial exposures has focused mainly on the respiratory effects of endotoxin, but a recent study suggests that not all endotoxin is the same; endotoxin from some species is proinflammatory, whereas endotoxin from other species is anti-inflammatory. Work with animals can change the adult human microbiome, likely through colonization. Early studies in military personnel and animal models of gulf war illness show that military exposures change the gut microbiome and increase gut permeability. Heavy metal and particulate matter exposure, which are often elevated in occupational settings, also change the gut microbiome.

SUMMARY: An emerging body of literature shows that work-related exposures can change the human microbiome. The health effects of these changes are currently not well studied. If work exposures lead to disease through alterations in the human microbiome, exposure cessation without addressing changes to the human microbiome may be ineffective for disease prevention and treatment.

RevDate: 2018-12-05

O'Toole RF, SS Gautam (2018)

The host microbiome and impact of tuberculosis chemotherapy.

Tuberculosis (Edinburgh, Scotland), 113:26-29.

The treatment of Mycobacterium tuberculosis infection is often viewed in isolation from other human microbial symbionts. Understandably, the clinical priority is eliminating active or latent tuberculosis (TB) in patients. With the increasing resolution of molecular biology technologies, it is becoming apparent that antibiotic treatment can perturb the homeostasis of the host microbiome. For example, dysbiosis of the gut microbiota has been associated with an increased risk of the development of asthma, obesity and diabetes. Therefore, fundamental questions include: Does TB chemotherapy cause disruption of the human microbiome and adverse effects in patients; and are there signature taxa of dysbiosis following TB treatment. In this review, we examine recent research on the detection of changes in the microbiome during antibiotic administration and discuss specific findings that relate to the impact of anti-tubercular chemotherapy.

RevDate: 2018-12-04

Brenner LA, Hoisington AJ, Stearns-Yoder KA, et al (2018)

Military-Related Exposures, Social Determinants of Health, and Dysbiosis: The United States-Veteran Microbiome Project (US-VMP).

Frontiers in cellular and infection microbiology, 8:400.

Significant effort has been put forth to increase understanding regarding the role of the human microbiome in health- and disease-related processes. In turn, the United States (US) Veteran Microbiome Project (US-VMP) was conceptualized as a means by which to serially collect microbiome and health-related data from those seeking care within the Veterans Health Administration (VHA). In this manuscript, exposures related to military experiences, as well as conditions and health-related factors among patients seen in VHA clinical settings are discussed in relation to common psychological and physical outcomes. Upon enrollment in the study, Veterans complete psychometrically sound (i.e., reliable and valid) measures regarding their past and current medical history. Participants also provide skin, oral, and gut microbiome samples, and permission to track their health status via the VHA electronic medical record. To date, data collection efforts have been cross-diagnostic. Within this manuscript, we describe current data collection practices and procedures, as well as highlight demographic, military, and psychiatric characteristics of the first 188 Veterans enrolled in the study. Based on these findings, we assert that this cohort is unique as compared to those enrolled in recent large-scale studies of the microbiome. To increase understanding regarding disease and health among diverse cohorts, efforts such as the US-VMP are vital. Ongoing barriers and facilitators to data collection are discussed, as well as future research directions, with an emphasis on the importance of shifting current thinking regarding the microbiome from a focus on normalcy and dysbiosis to health promotion and disease prevention.

RevDate: 2018-12-04

Mathias M (2018)

Autointoxication and historical precursors of the microbiome-gut-brain axis.

Microbial ecology in health and disease, 29(2):1548249 pii:1548249.

This article focuses on autointoxication, a discredited medical theory from the late nineteenth century that provides important points of reflection for today's research on the role of microbes in the human gut for mental health. It considers how the theory of autointoxication, which came into great prominence amongst physicians and the general public worldwide, fell from grace by the middle of the twentieth century, and briefly asks why studies of the human microbiome are now back in vogue. It departs from earlier articles on the topic firstly by arguing that autointoxication theory was especially prevalent in France, and secondly by focusing on the application of this theory to mental health. Bringing to light medical treatises and theses from this period which have so far remained unexamined, it shows that examining the development and reception of medical theories form the past can help us today in understanding both the pitfalls and promise of research in this area.

RevDate: 2018-11-29

Ando H (2018)

[Creation of synthetic bacterial viruses].

Nihon saikingaku zasshi. Japanese journal of bacteriology, 73(4):201-210.

Bacteria are closely related with human health and diseases. For example, the emergence of drug-resistant bacteria is a serious problem in the world. Studying the human microbiome shows its important role for our health. But we have very limited tools to edit bacterial population. Antibiotics are generally broad-spectrum and unable to kill only bad bacteria. The natural enemies of bacteria, called bacteriophage (phage), have highly specific host range, and thus promising candidates for targeted bacterial population editing. However, isolation and characterization of natural phages can be a time-, labor- and cost-intensive way. Also, developing phage-based therapeutics and diagnostics is limited by the difficulty of engineering phages. Here, I describe a phage genome-engineering platform and synthetic phages with tunable host ranges to overcome these challenges.

RevDate: 2018-11-28

McCord B, Gauthier Q, Cho S, et al (2018)

Forensic DNA Analysis.

Analytical chemistry [Epub ahead of print].

This review focuses on recent developments in forensic DNA typing. It highlights important recent advances and issues in forensic human identification and identifies representative papers. It is not intended to be comprehensive. The review is divided into several important topic areas. These include developments in forensic serology using RNA, proteomic, and Epigenetic markers, and methods for human identification using short tandem repeats, single nucleotide polymorphisms, and insertion deletions. Sequencing methods for autosomal DNA, sex linked DNA, and mitochondrial DNA are included as well as for the human microbiome. New technologies are also featured, such as real time PCR, microfluidics, integrated rapid PCR systems, and massively parallel sequencing. Expert systems have also been developed to assist with the analysis of data from these complex analytical tools.

RevDate: 2018-11-28

Espinoza JL, Harkins DM, Torralba M, et al (2018)

Supragingival Plaque Microbiome Ecology and Functional Potential in the Context of Health and Disease.

mBio, 9(6): pii:mBio.01631-18.

To address the question of how microbial diversity and function in the oral cavities of children relates to caries diagnosis, we surveyed the supragingival plaque biofilm microbiome in 44 juvenile twin pairs. Using shotgun sequencing, we constructed a genome encyclopedia describing the core supragingival plaque microbiome. Caries phenotypes contained statistically significant enrichments in specific genome abundances and distinct community composition profiles, including strain-level changes. Metabolic pathways that are statistically associated with caries include several sugar-associated phosphotransferase systems, antimicrobial resistance, and metal transport. Numerous closely related previously uncharacterized microbes had substantial variation in central metabolism, including the loss of biosynthetic pathways resulting in auxotrophy, changing the ecological role. We also describe the first complete Gracilibacteria genomes from the human microbiome. Caries is a microbial community metabolic disorder that cannot be described by a single etiology, and our results provide the information needed for next-generation diagnostic tools and therapeutics for caries.IMPORTANCE Oral health has substantial economic importance, with over $100 billion spent on dental care in the United States annually. The microbiome plays a critical role in oral health, yet remains poorly classified. To address the question of how microbial diversity and function in the oral cavities of children relate to caries diagnosis, we surveyed the supragingival plaque biofilm microbiome in 44 juvenile twin pairs. Using shotgun sequencing, we constructed a genome encyclopedia describing the core supragingival plaque microbiome. This unveiled several new previously uncharacterized but ubiquitous microbial lineages in the oral microbiome. Caries is a microbial community metabolic disorder that cannot be described by a single etiology, and our results provide the information needed for next-generation diagnostic tools and therapeutics for caries.

RevDate: 2018-11-27

Kim JW, Lee JS, Kim JH, et al (2018)

Comparison of Microbiota Variation in Korean Healthy Adolescents with Adults Suggests Notable Maturity Differences.

Omics : a journal of integrative biology [Epub ahead of print].

Comparative studies of microbiome variation in world populations and different developmental stages of organisms are essential to decipher the linkages among microbiome, health, and disease. Notably, the gut microbiota are believed to mature in early life. In this context, we compared the gut microbiota diversity in Korean adolescent healthy samples (KAHSs) to healthy Korean adults (HKAs) as well as the Human Microbiome Project healthy samples (HMPHSs), the latter being one of the largest adult cohorts, based on organismal composition, alpha- and beta-diversities, function/pathway prediction analysis, and co-occurrence networks. We found that the gut microbiota compositions, including the ratios of firmicutes to bacteroidetes, between KAHSs and HMPHSs were different, and the diversities of KAHSs were less than those of HMPHSs. The predicted functions, for example, secondary bile acid synthesis and insulin signaling of KAHSs and HMPHSs, were also significantly different. Genus-level networks showed that co-occurrences among different taxa more frequently happened in HMPHSs than in KAHSs. Even though both KAHSs and HMPHSs represent healthy microbiomes, comparisons showed substantial differences, likely implicating different diets, environments, and demographics. Interestingly, we observed lower microbial diversities and less frequent co-occurrences among different taxa in KAHSs than adult HMPHSs and HKAs. These new findings collectively suggest that the adolescent gut microbiota in the present Korean sample did not reach the extent of maturity of adult microbiota diversity. In all, further population studies of microbiome variation across geographies and developmental stages are warranted, and should usefully inform future diagnostics and therapeutics innovation targeting the microbiome.

RevDate: 2018-11-30

Sinha R, Ahsan H, Blaser M, et al (2018)

Next steps in studying the human microbiome and health in prospective studies, Bethesda, MD, May 16-17, 2017.

Microbiome, 6(1):210 pii:10.1186/s40168-018-0596-z.

The National Cancer Institute (NCI) sponsored a 2-day workshop, "Next Steps in Studying the Human Microbiome and Health in Prospective Studies," in Bethesda, Maryland, May 16-17, 2017. The workshop brought together researchers in the field to discuss the challenges of conducting microbiome studies, including study design, collection and processing of samples, bioinformatics and statistical methods, publishing results, and ensuring reproducibility of published results. The presenters emphasized the great potential of microbiome research in understanding the etiology of cancer. This report summarizes the workshop and presents practical suggestions for conducting microbiome studies, from workshop presenters, moderators, and participants.

RevDate: 2018-11-27

Cristofori F, Indrio F, Miniello VL, et al (2018)

Probiotics in Celiac Disease.

Nutrients, 10(12): pii:nu10121824.

Recently, the interest in the human microbiome and its interplay with the host has exploded and provided new insights on its role in conferring host protection and regulating host physiology, including the correct development of immunity. However, in the presence of microbial imbalance and particular genetic settings, the microbiome may contribute to the dysfunction of host metabolism and physiology, leading to pathogenesis and/or the progression of several diseases. Celiac disease (CD) is a chronic autoimmune enteropathy triggered by dietary gluten exposure in genetically predisposed individuals. Despite ascertaining that gluten is the trigger in CD, evidence has indicated that intestinal microbiota is somehow involved in the pathogenesis, progression, and clinical presentation of CD. Indeed, several studies have reported imbalances in the intestinal microbiota of patients with CD that are mainly characterized by an increased abundance of Bacteroides spp. and a decrease in Bifidobacterium spp. The evidence that some of these microbial imbalances still persist in spite of a strict gluten-free diet and that celiac patients suffering from persistent gastrointestinal symptoms have a desert gut microbiota composition further support its close link with CD. All of this evidence gives rise to the hypothesis that probiotics might play a role in this condition. In this review, we describe the recent scientific evidences linking the gut microbiota in CD, starting from the possible role of microbes in CD pathogenesis, the attempt to define a microbial signature of disease, the effect of a gluten-free diet and host genetic assets regarding microbial composition to end in the exploration of the proof of concept of probiotic use in animal models to the most recent clinical application of selected probiotic strains.

RevDate: 2018-11-30

Jonsson V, Österlund T, Nerman O, et al (2018)

Modelling of zero-inflation improves inference of metagenomic gene count data.

Statistical methods in medical research [Epub ahead of print].

Metagenomics enables the study of gene abundances in complex mixtures of microorganisms and has become a standard methodology for the analysis of the human microbiome. However, gene abundance data is inherently noisy and contains high levels of biological and technical variability as well as an excess of zeros due to non-detected genes. This makes the statistical analysis challenging. In this study, we present a new hierarchical Bayesian model for inference of metagenomic gene abundance data. The model uses a zero-inflated overdispersed Poisson distribution which is able to simultaneously capture the high gene-specific variability as well as zero observations in the data. By analysis of three comprehensive datasets, we show that zero-inflation is common in metagenomic data from the human gut and, if not correctly modelled, it can lead to substantial reductions in statistical power. We also show, by using resampled metagenomic data, that our model has, compared to other methods, a higher and more stable performance for detecting differentially abundant genes. We conclude that proper modelling of the gene-specific variability, including the excess of zeros, is necessary to accurately describe gene abundances in metagenomic data. The proposed model will thus pave the way for new biological insights into the structure of microbial communities.

RevDate: 2018-11-22

Mendez R, Banerjee S, Bhattacharya SK, et al (2018)

Lung inflammation and disease: A perspective on microbial homeostasis and metabolism.

IUBMB life [Epub ahead of print].

It is now well appreciated that the human microbiome plays a significant role in a number of processes in the body, significantly affecting its metabolic, inflammatory, and immune homeostasis. Recent research has revealed that almost every mucosal surface in the human body is associated with a resident commensal microbiome of its own. While the gut microbiome and its role in regulation of host metabolism along with its alteration in a disease state has been well studied, there is a lacuna in understanding the resident microbiota of other mucosal surfaces. Among these, the scientific information on the role of lung microbiota in pulmonary diseases is currently severely limited. Historically, lungs have been considered to be sterile and lung diseases have only been studied in the context of bacterial pathogenesis. Recently however, studies have revealed a resilient microbiome in the upper and lower respiratory tracts and there is increased evidence on its central role in respiratory diseases. Knowledge of lung microbiome and its metabolic fallout (local and systemic) is still in its nascent stages and attracting immense interest in recent times. In this review, we will provide a perspective on lung-associated metabolic disorders defined for lung diseases (e.g., chronic obstructive pulmonary disease, asthma, and respiratory depression due to infection) and correlate it with lung microbial perturbation. Such perturbations may be due to altered biochemical or metabolic stress as well. Finally, we will draw evidence from microbiome and classical microbiology literature to demonstrate how specific lung morbidities associate with specific metabolic characteristics of the disease, and with the role of microbiome in this context. © 2018 IUBMB Life, 1-14, 2018.

RevDate: 2018-11-22

Beilsmith K, Thoen MPM, Brachi B, et al (2018)

Genome-Wide Association studies on the phyllosphere microbiome: embracing complexity in host-microbe interactions.

The Plant journal : for cell and molecular biology [Epub ahead of print].

Environmental sequencing shows that plants harbor complex communities of microbes that vary across environments. However, many approaches for mapping plant genetic variation to microbe-related traits were developed in the relatively simple context of binary host-microbe interactions under controlled conditions. Recent advances in sequencing and statistics make genome-wide association studies (GWAS) an increasingly promising approach for identifying the plant genetic variation associated with microbes in a community context. This review discusses early efforts at GWAS of the plant phyllosphere microbiome and the outlook for future studies based on human microbiome GWAS. A workflow for GWAS of the phyllosphere microbiome is then presented, with particular attention to how perspectives on the mechanisms, evolution, and environmental dependence of plant-microbe interactions will influence the choice of traits to be mapped. This article is protected by copyright. All rights reserved.

RevDate: 2018-11-22

Wang H, Kang D, Zhou XD, et al (2018)

[Prevention of infectious diseases through microecology modulation techniques].

Hua xi kou qiang yi xue za zhi = Huaxi kouqiang yixue zazhi = West China journal of stomatology, 36(5):564-567.

The microbe is small in volume, but large in quantity and species. The symbiotic microbe, which is far more than human cells, code millions times of genes than human being. Somatic cells and these symbiotic microbe distributing in human body skin, respiratory tract, oral cavity and gastrointestinal tract, urinary tract and other parts form a complex ecosystem whose dynamic balance is highly related to body health. With the successful implementation of Human Microbiome Project, more attentions have been paid to the next generation microbiome technologies. New tools and methods for ecological regulation of human microbiome are emerging. The way we improve the world of human microbiology will be more convenient. This paper will make a review on the modulation techniques of human microbiome.

RevDate: 2018-11-21

Barbara G, Cremon C, F Azpiroz (2018)

Probiotics in irritable bowel syndrome: Where are we?.

Neurogastroenterology and motility : the official journal of the European Gastrointestinal Motility Society, 30(12):e13513.

We have only recently begun to understand how alterations of the intestinal microbial ecosystem lead to the disruption of host-microbial interactions and are associated with diseases, including functional gastrointestinal disorders such as irritable bowel syndrome (IBS). Although we are still far from understanding the human microbiome, gut microbiota is already a therapeutic target. Probiotics are live microorganisms that, when administered in adequate amounts, confer a health benefit to the host and may represent a therapeutic option for diseases characterized by dysbiosis such as IBS. Meta-analyses suggest that probiotics provide a therapeutic gain over placebo on global symptoms with a high safety profile in IBS patients. However, the mechanisms by which they provide benefit in IBS remain virtually unknown. In this issue of Neurogastroenterology and Motility, BIO-25, a multispecies probiotic, did not significantly modify the composition of the fecal microbiota, but interestingly, patients with specific basal features of the intestinal microbial ecosystem improved with treatment. Based on these data, it is tantalizing to speculate that microbiota composition serves as a predictor of the response to probiotic intervention. This mini-review addresses unresolved issues related to mechanisms through which probiotics may exert their beneficial effects, the biological, as well as clinical predictors of favorable outcomes in IBS and finally considers possible new directions for future studies.

RevDate: 2018-11-29

Chen B, Zhao Y, Li S, et al (2018)

Variations in oral microbiome profiles in rheumatoid arthritis and osteoarthritis with potential biomarkers for arthritis screening.

Scientific reports, 8(1):17126 pii:10.1038/s41598-018-35473-6.

The key to arthritis management is early diagnosis and treatment to prevent further joint destruction and maximize functional ability. Osteoarthritis (OA) and rheumatoid arthritis (RA) are two common types of arthritis that the primary care provider must differentiate, in terms of diagnosis and treatment. Effective and non-invasive strategies for early detection and disease identification are sorely needed. Growing evidence suggests that RA has a correlation with oral microbiome and may be affected by its dynamic variations. There is already a study comparing oral microbiome in patients with RA and OA, however, it did not screen for potential biomarkers for arthritis. In this study, we assessed the oral microbiome in saliva samples from 110 RA patients, 67 OA patients and 155 healthy subjects, using 16S rRNA gene amplicon sequencing. The structure and differences in oral microbiome between RA, OA and healthy subjects were analyzed. Eight oral bacterial biomarkers were identified to differentiate RA from OA. This report provides proof of oral microbiota as an informative source for discovering non-invasive biomarkers for arthritis screening.

RevDate: 2018-11-19

Rajakovich LJ, EP Balskus (2018)

Metabolic functions of the human gut microbiota: the role of metalloenzymes.

Natural product reports [Epub ahead of print].

Covering: up to the end of 2017The human body is composed of an equal number of human and microbial cells. While the microbial community inhabiting the human gastrointestinal tract plays an essential role in host health, these organisms have also been connected to various diseases. Yet, the gut microbial functions that modulate host biology are not well established. In this review, we describe metabolic functions of the human gut microbiota that involve metalloenzymes. These activities enable gut microbial colonization, mediate interactions with the host, and impact human health and disease. We highlight cases in which enzyme characterization has advanced our understanding of the gut microbiota and examples that illustrate the diverse ways in which metalloenzymes facilitate both essential and unique functions of this community. Finally, we analyze Human Microbiome Project sequencing datasets to assess the distribution of a prominent family of metalloenzymes in human-associated microbial communities, guiding future enzyme characterization efforts.

RevDate: 2018-11-19

Guerin E, Shkoporov A, Stockdale SR, et al (2018)

Biology and Taxonomy of crAss-like Bacteriophages, the Most Abundant Virus in the Human Gut.

Cell host & microbe, 24(5):653-664.e6.

CrAssphages represent the most abundant virus in the human gut microbiota, but the lack of available genome sequences for comparison has kept them enigmatic. Recently, sequence-based classification of distantly related crAss-like phages from multiple environments was reported, leading to a proposed familial-level taxonomic group. Here, we assembled the metagenomic sequencing reads from 702 human fecal virome/phageome samples and analyzed 99 complete circular crAss-like phage genomes and 150 contigs ≥70 kb. In silico comparative genomics and taxonomic analysis enabled a classification scheme of crAss-like phages from human fecal microbiomes into four candidate subfamilies composed of ten candidate genera. Laboratory analysis was performed on fecal samples from an individual harboring seven distinct crAss-like phages. We achieved crAss-like phage propagation in ex vivo human fecal fermentations and visualized short-tailed podoviruses by electron microscopy. Mass spectrometry of a crAss-like phage capsid protein could be linked to metagenomic sequencing data, confirming crAss-like phage structural annotations.

RevDate: 2018-11-22

Hillmann B, Al-Ghalith GA, Shields-Cutler RR, et al (2018)

Evaluating the Information Content of Shallow Shotgun Metagenomics.

mSystems, 3(6): pii:mSystems00069-18.

Although microbial communities are associated with human, environmental, plant, and animal health, there exists no cost-effective method for precisely characterizing species and genes in such communities. While deep whole-metagenome shotgun (WMS) sequencing provides high taxonomic and functional resolution, it is often prohibitively expensive for large-scale studies. The prevailing alternative, 16S rRNA gene amplicon (16S) sequencing, often does not resolve taxonomy past the genus level and provides only moderately accurate predictions of the functional profile; thus, there is currently no widely accepted approach to affordable, high-resolution, taxonomic, and functional microbiome analysis. To address this technology gap, we evaluated the information content of shallow shotgun sequencing with as low as 0.5 million sequences per sample as an alternative to 16S sequencing for large human microbiome studies. We describe a library preparation protocol enabling shallow shotgun sequencing at approximately the same per-sample cost as 16S sequencing. We analyzed multiple real and simulated biological data sets, including two novel human stool samples with ultradeep sequencing of 2.5 billion sequences per sample, and found that shallow shotgun sequencing recovers more-accurate species-level taxonomic and functional profiles of the human microbiome than 16S sequencing. We discuss the inherent limitations of shallow shotgun sequencing and note that 16S sequencing remains a valuable and important method for taxonomic profiling of novel environments. Although deep WMS sequencing remains the gold standard for high-resolution microbiome analysis, we recommend that researchers consider shallow shotgun sequencing as a useful alternative to 16S sequencing for large-scale human microbiome research studies where WMS sequencing may be cost-prohibitive. IMPORTANCE A common refrain in recent microbiome-related academic meetings is that the field needs to move away from broad taxonomic surveys using 16S sequencing and toward more powerful longitudinal studies using shotgun sequencing. However, performing deep shotgun sequencing in large longitudinal studies remains prohibitively expensive for all but the most well-funded research labs and consortia, which leads many researchers to choose 16S sequencing for large studies, followed by deep shotgun sequencing on a subset of targeted samples. Here, we show that shallow- or moderate-depth shotgun sequencing may be used by researchers to obtain species-level taxonomic and functional data at approximately the same cost as amplicon sequencing. While shallow shotgun sequencing is not intended to replace deep shotgun sequencing for strain-level characterization, we recommend that microbiome scientists consider using shallow shotgun sequencing instead of 16S sequencing for large-scale human microbiome studies.

RevDate: 2018-11-15

Jha AR, Davenport ER, Gautam Y, et al (2018)

Gut microbiome transition across a lifestyle gradient in Himalaya.

PLoS biology, 16(11):e2005396 pii:pbio.2005396.

The composition of the gut microbiome in industrialized populations differs from those living traditional lifestyles. However, it has been difficult to separate the contributions of human genetic and geographic factors from lifestyle. Whether shifts away from the foraging lifestyle that characterize much of humanity's past influence the gut microbiome, and to what degree, remains unclear. Here, we characterize the stool bacterial composition of four Himalayan populations to investigate how the gut community changes in response to shifts in traditional human lifestyles. These groups led seminomadic hunting-gathering lifestyles until transitioning to varying levels of agricultural dependence upon farming. The Tharu began farming 250-300 years ago, the Raute and Raji transitioned 30-40 years ago, and the Chepang retain many aspects of a foraging lifestyle. We assess the contributions of dietary and environmental factors on their gut-associated microbes and find that differences in the lifestyles of Himalayan foragers and farmers are strongly correlated with microbial community variation. Furthermore, the gut microbiomes of all four traditional Himalayan populations are distinct from that of the Americans, indicating that industrialization may further exacerbate differences in the gut community. The Chepang foragers harbor an elevated abundance of taxa associated with foragers around the world. Conversely, the gut microbiomes of the populations that have transitioned to farming are more similar to those of Americans, with agricultural dependence and several associated lifestyle and environmental factors correlating with the extent of microbiome divergence from the foraging population. The gut microbiomes of Raute and Raji reveal an intermediate state between the Chepang and Tharu, indicating that divergence from a stereotypical foraging microbiome can occur within a single generation. Our results also show that environmental factors such as drinking water source and solid cooking fuel are significantly associated with the gut microbiome. Despite the pronounced differences in gut bacterial composition across populations, we found little differences in alpha diversity across lifestyles. These findings in genetically similar populations living in the same geographical region establish the key role of lifestyle in determining human gut microbiome composition and point to the next challenging steps of determining how large-scale gut microbiome reconfiguration impacts human biology.

RevDate: 2018-11-15

Berry D (2018)

Up-close-and-personal with the human microbiome.

Environmental microbiology reports [Epub ahead of print].

RevDate: 2018-11-14

Daisley BA, Monachese M, Trinder M, et al (2018)

Immobilization of cadmium and lead by Lactobacillus rhamnosus GR-1 mitigates apical-to-basolateral heavy metal translocation in a Caco-2 model of the intestinal epithelium.

Gut microbes [Epub ahead of print].

Heavy metals are highly toxic elements that contaminate the global food supply and affect human and wildlife health. Purification technologies are often too expensive or not practically applicable for large-scale implementation, especially in impoverished nations where heavy metal contamination is widespread. Lactobacillus rhamnosus GR-1 (LGR-1) was shown in previous work to reduce heavy metal bioaccumulation in a Tanzanian cohort of women and children through indeterminant mechanisms. Here, it was hypothesized that LGR-1 could sequester the heavy metals lead (Pb) and cadmium (Cd), thereby reducing their absorption across intestinal epithelium. LGR-1 and other lactobacilli significantly reduced the amount of Pb and Cd in solution at all concentrations tested (0.5 mg/L - 50 mg/L) and exhibited sustained binding profiles over a 48-hour period. Relative binding efficiency of LGR-1 decreased as Pb concentration increased, with an absolute minimum binding threshold apparent at concentrations of 2 mg/L and above. Electron microscopy revealed that Pb formed irregular cell-surface clusters on LGR-1, while Cd appeared to form intracellular polymeric clusters. Additionally, LGR-1 was able to significantly reduce apical-to-basolateral translocation of Pb and Cd in a Caco-2 model of the intestinal epithelium. These findings demonstrate the absorbent properties of LGR-1 can immobilize Pb and Cd, effectively reducing their translocation across the intestinal epithelium in vitro. Oral administration of heavy metal-binding Lactobacillus spp. (many of which are known human symbionts and strains of established probiotics) may offer a simple and effective means to reduce the amount of heavy metals absorbed from foods in contaminated regions of the world.

RevDate: 2018-11-15

Frioux C, Fremy E, Trottier C, et al (2018)

Scalable and exhaustive screening of metabolic functions carried out by microbial consortia.

Bioinformatics (Oxford, England), 34(17):i934-i943.

Motivation: The selection of species exhibiting metabolic behaviors of interest is a challenging step when switching from the investigation of a large microbiota to the study of functions effectiveness. Approaches based on a compartmentalized framework are not scalable. The output of scalable approaches based on a non-compartmentalized modeling may be so large that it has neither been explored nor handled so far.

Results: We present the Miscoto tool to facilitate the selection of a community optimizing a desired function in a microbiome by reporting several possibilities which can be then sorted according to biological criteria. Communities are exhaustively identified using logical programming and by combining the non-compartmentalized and the compartmentalized frameworks. The benchmarking of 4.9 million metabolic functions associated with the Human Microbiome Project, shows that Miscoto is suited to screen and classify metabolic producibility in terms of feasibility, functional redundancy and cooperation processes involved. As an illustration of a host-microbial system, screening the Recon 2.2 human metabolism highlights the role of different consortia within a family of 773 intestinal bacteria.

Miscoto source code, instructions for use and examples are available at: https://github.com/cfrioux/miscoto.

RevDate: 2018-11-15

Yost S, Stashenko P, Choi Y, et al (2018)

Increased virulence of the oral microbiome in oral squamous cell carcinoma revealed by metatranscriptome analyses.

International journal of oral science, 10(4):32 pii:10.1038/s41368-018-0037-7.

Oral squamous cell carcinoma (OSCC) is the most prevalent and most commonly studied oral cancer. However, there is a void regarding the role that the oral microbiome may play in OSCC. Although the relationship between microbial community composition and OSCC has been thoroughly investigated, microbial profiles of the human microbiome in cancer are understudied. Here we performed a small pilot study of community-wide metatranscriptome analysis to profile mRNA expression in the entire oral microbiome in OSCC to reveal molecular functions associated with this disease. Fusobacteria showed a statistically significantly higher number of transcripts at tumour sites and tumour-adjacent sites of cancer patients compared to the healthy controls analysed. Regardless of the community composition, specific metabolic signatures were consistently found in disease. Activities such as iron ion transport, tryptophanase activity, peptidase activities and superoxide dismutase were over-represented in tumour and tumour-adjacent samples when compared to the healthy controls. The expression of putative virulence factors in the oral communities associated with OSCC showed that activities related to capsule biosynthesis, flagellum synthesis and assembly, chemotaxis, iron transport, haemolysins and adhesins were upregulated at tumour sites. Moreover, activities associated with protection against reactive nitrogen intermediates, chemotaxis, flagellar and capsule biosynthesis were also upregulated in non-tumour sites of cancer patients. Although they are preliminary, our results further suggest that Fusobacteria may be the leading phylogenetic group responsible for the increase in expression of virulence factors in the oral microbiome of OSCC patients.

RevDate: 2018-11-27

Ventura Spagnolo E, Stassi C, Mondello C, et al (2018)

Forensic microbiology applications: A systematic review.

Legal medicine (Tokyo, Japan), 36:73-80 pii:S1344-6223(18)30153-6 [Epub ahead of print].

According to the Human Microbiome Project (HMP), a healthy human body contains ten times more microbes than human cells. Microbial communities colonize different organs of the body, playing fundamental roles both in human health and disease. Despite the vast scientific knowledge of the role of microbial communities in a living body, little is known at present about microbial changes occurring after death, thus leading many authors to investigate the composition of the thanatomicrobiome and its potential applications in the forensic field. The aim of the following review is to provide a general overview of the advances of postmortem microbiology research, mainly focusing on the role of microbiological investigations carried out on internal organs and fluids. To this end, a total of 19 studies have been sistematically reviewed, each one chosen according to specific inclusion/exclusion criteria. The selected studies assess the contribution of contamination, postmortem transmigration and agonal spread to microbial isolation from dead body samples, and shed light on the role of postmortem microbiological investigations in several forensic fields, such as cause of death or PMI determination.

RevDate: 2018-11-27

Fonkou MD, Dufour JC, Dubourg G, et al (2018)

Repertoire of bacterial species cultured from the human oral cavity and respiratory tract.

Future microbiology, 13:1611-1624.

While the gut microbiota is currently in the spotlight, the airway microbiome has been recently associated with several pulmonary diseases and carcinogenesis. As there are several biases associated with high-throughput sequencing methods, cultivation techniques are crucial for the investigation of the human microbiome. We thus aimed to build an exhaustive database, including a list of microbes isolated by culture from respiratory specimens, by performing a review of the literature. Herein, we have listed a total of 756 species cultured from the human respiratory tract. This represents 27.23% of the overall bacterial richness captured from human being by culture methods. This repertoire could be valuable for the elucidation of the interactions between the respiratory microbiome and human health.

RevDate: 2018-11-14

Bratburd JR, Keller C, Vivas E, et al (2018)

Gut Microbial and Metabolic Responses to Salmonella enterica Serovar Typhimurium and Candida albicans.

mBio, 9(6): pii:mBio.02032-18.

The gut microbiota confers resistance to pathogens of the intestinal ecosystem, yet the dynamics of pathogen-microbiome interactions and the metabolites involved in this process remain largely unknown. Here, we use gnotobiotic mice infected with the virulent pathogen Salmonella enterica serovar Typhimurium or the opportunistic pathogen Candida albicans in combination with metagenomics and discovery metabolomics to identify changes in the community and metabolome during infection. To isolate the role of the microbiota in response to pathogens, we compared mice monocolonized with the pathogen, uninfected mice "humanized" with a synthetic human microbiome, or infected humanized mice. In Salmonella-infected mice, by 3 days into infection, microbiome community structure and function changed substantially, with a rise in Enterobacteriaceae strains and a reduction in biosynthetic gene cluster potential. In contrast, Candida-infected mice had few microbiome changes. The LC-MS metabolomic fingerprint of the cecum differed between mice monocolonized with either pathogen and humanized infected mice. Specifically, we identified an increase in glutathione disulfide, glutathione cysteine disulfide, inosine 5'-monophosphate, and hydroxybutyrylcarnitine in mice infected with Salmonella in contrast to uninfected mice and mice monocolonized with Salmonella These metabolites potentially play a role in pathogen-induced oxidative stress. These results provide insight into how the microbiota community members interact with each other and with pathogens on a metabolic level.IMPORTANCE The gut microbiota is increasingly recognized for playing a critical role in human health and disease, especially in conferring resistance to both virulent pathogens such as Salmonella, which infects 1.2 million people in the United States every year (E. Scallan, R. M. Hoekstra, F. J. Angulo, R. V. Tauxe, et al., Emerg Infect Dis 17:7-15, 2011, https://doi.org/10.3201/eid1701.P11101), and opportunistic pathogens like Candida, which causes an estimated 46,000 cases of invasive candidiasis each year in the United States (Centers for Disease Control and Prevention, Antibiotic Resistance Threats in the United States, 2013, 2013). Using a gnotobiotic mouse model, we investigate potential changes in gut microbial community structure and function during infection using metagenomics and metabolomics. We observe that changes in the community and in biosynthetic gene cluster potential occur within 3 days for the virulent Salmonella enterica serovar Typhimurium, but there are minimal changes with a poorly colonizing Candida albicans In addition, the metabolome shifts depending on infection status, including changes in glutathione metabolites in response to Salmonella infection, potentially in response to host oxidative stress.

RevDate: 2018-11-07

Ojo-Okunola A, Nicol M, E du Toit (2018)

Human Breast Milk Bacteriome in Health and Disease.

Nutrients, 10(11): pii:nu10111643.

It is well-known that, beyond nutritional components, human breast milk (HBM) contains a wide variety of non-nutritive bio-factors perfectly suited for the growing infant. In the pre-2000 era, HBM was considered sterile and devoid of micro-organisms. Though HBM was not included as part of the human microbiome project launched in 2007, great strides have been made in studying the bacterial diversity of HBM in both a healthy state and diseased state, and in understanding their role in infant health. HBM provides a vast array of beneficial micro-organisms that play a key role in colonizing the infant's mucosal system, including that of the gut. They also have a role in priming the infant's immune system and supporting its maturation. In this review, we provide an in-depth and updated insight into the immunomodulatory, metabolic, and anti-infective role of HBM bacteriome (bacterial community) and its effect on infant health. We also provide key information from the literature by exploring the possible origin of microbial communities in HBM, the bacterial diversity in this niche and the determinants influencing the HBM bacteriome. Lastly, we investigate the role of the HBM bacteriome in maternal infectious disease (human immunodeficiency virus (HIV) and mastitis)), and cancer. Key gaps in HBM bacterial research are also identified.

RevDate: 2018-11-06

Tirosh O, Conlan S, Deming C, et al (2018)

Expanded skin virome in DOCK8-deficient patients.

Nature medicine pii:10.1038/s41591-018-0211-7 [Epub ahead of print].

Human microbiome studies have revealed the intricate interplay of host immunity and bacterial communities to achieve homeostatic balance. Healthy skin microbial communities are dominated by bacteria with low viral representation1-3, mainly bacteriophage. Specific eukaryotic viruses have been implicated in both common and rare skin diseases, but cataloging skin viral communities has been limited. Alterations in host immunity provide an opportunity to expand our understanding of microbial-host interactions. Primary immunodeficient patients manifest with various viral, bacterial, fungal, and parasitic infections, including skin infections4. Dedicator of cytokinesis 8 (DOCK8) deficiency is a rare primary human immunodeficiency characterized by recurrent cutaneous and systemic infections, as well as atopy and cancer susceptibility5. DOCK8, encoding a guanine nucleotide exchange factor highly expressed in lymphocytes, regulates actin cytoskeleton, which is critical for migration through collagen-dense tissues such as skin6. Analyzing deep metagenomic sequencing data from DOCK8-deficient skin samples demonstrated a notable increase in eukaryotic viral representation and diversity compared with healthy volunteers. De novo assembly approaches identified hundreds of novel human papillomavirus genomes, illuminating microbial dark matter. Expansion of the skin virome in DOCK8-deficient patients underscores the importance of immune surveillance in controlling eukaryotic viral colonization and infection.

RevDate: 2018-11-29

Woerner AE, Novroski NMM, Wendt FR, et al (2018)

Forensic human identification with targeted microbiome markers using nearest neighbor classification.

Forensic science international. Genetics, 38:130-139 pii:S1872-4973(18)30373-9 [Epub ahead of print].

From the perspective of forensics genetics, the human microbiome is a rich, relatively untapped resource for human identity testing. Since it varies within and among people, and perhaps temporally, the potential forensic applications of the use of the microbiome can exceed that of human identification. However, the same inherent variability in microbial distributions may pose a substantial barrier to forming predictions on an individual as the source of the microbial sample unless stable signatures of the microbiome are identified and targeted. One of the more commonly adopted strategies for microbial human identification relies on quantifying which taxa are present and their respective abundance levels. It remains an open question if such microbial signatures are more individualizing than estimates of the degree of genetic relatedness between microbial samples. This study attempts to address this question by contrasting two prediction strategies. The first approach uses phylogenetic distance to predict the host individual; thus it operates under the premise that microbes within individuals are more closely related than microbes between/among individuals. The second approach uses population genetic measures of diversity at clade-specific markers, serving as a fine-grained assessment of microbial composition and quantification. Both assessments were performed using targeted sequencing of 286 markers from 22 microbial taxa sampled in 51 individuals across three body sites measured in triplicate. Nearest neighbor and reverse nearest neighbor classifiers were constructed based on the pooled data and yielded 71% and 78% accuracy, respectively, when diversity was considered, and performed significantly worse when a phylogenetic distance was used (54% and 63% accuracy, respectively). However, empirical estimates of classification accuracy were 100% when conditioned on a maximum nearest neighbor distance when diversity was used, while identification based on a phylogenetic distance failed to reach saturation. These findings suggest that microbial strain composition is more individualizing than that of a phylogeny, perhaps indicating that microbial composition may be more individualizing than recent common ancestry. One inference that may be drawn from these findings is that host-environment interactions may maintain the targeted microbial profile and that this maintenance may not necessarily be repopulated by intra-individual microbial strains.

RevDate: 2018-11-05

Cogdill AP, Gaudreau PO, Arora R, et al (2018)

The Impact of Intratumoral and Gastrointestinal Microbiota on Systemic Cancer Therapy.

Trends in immunology, 39(11):900-920.

The human microbiome is a complex aggregate of microorganisms, and their genomes exert a number of influences crucial to the metabolic, immunologic, hormonal, and homeostatic function of the host. Recent work, both in preclinical mouse models and human studies, has shed light on the impact of gut and tumor microbiota on responses to systemic anticancer therapeutics. In light of this, strategies to target the microbiome to improve therapeutic responses are underway, including efforts to target gut and intratumoral microbes. Here, we discuss mechanisms by which microbiota may impact systemic and antitumor immunity, in addition to outstanding questions in the field. A deeper understanding of these is critical as we devise putative strategies to target the microbiome.

RevDate: 2018-11-04

Wang Q, Yang F, H Jia (2018)

Mining the Microbiome for Drug Targets.

Methods in enzymology, 610:59-72.

The human microbiome is our "other genome." Implicated in a growing list of complex diseases, for which genomic studies typically explain a portion of the disease susceptibility, the human gut microbiome has been at the spotlight for our understanding of human diseases. As the microbiome is intrinsically more variable than the human genome, it is important to take careful considerations at each step of a study. Here, we put forward our recommendations, which we envision would facilitate identification of true drug targets in the human microbiome in the colon as well as at other body sites.

RevDate: 2018-11-14

Wu BG, LN Segal (2018)

The Lung Microbiome and Its Role in Pneumonia.

Clinics in chest medicine, 39(4):677-689.

The use of next-generation sequencing and multiomic analysis reveals new insights on the identity of microbes in the lower airways blurring the lines between commensals and pathogens. Microbes are not found in isolation; rather they form complex metacommunities where microbe-host and microbe-microbe interactions play important roles on the host susceptibility to pathogens. In addition, the lower airway microbiota exert significant effects on host immune tone. Thus, this review highlights the roles that microbes in the respiratory tract play in the development of pneumonia.

RevDate: 2018-11-03

Junges R, Sturød K, Salvadori G, et al (2018)

Characterization of a signaling system in the oral commensal Streptococcus mitis that mediates interspecies communication with the pathogen Streptococcus pneumoniae.

Applied and environmental microbiology pii:AEM.02297-18 [Epub ahead of print].

Streptococcus mitis is found in the oral cavity and nasopharynx and forms a significant portion of the human microbiome. In this study, in silico analyses indicated the presence of an Rgg/SHP cell-to-cell communication system in S. mitis Although Rgg presented higher similarity to a repressor in Streptococcus pyogenes, auto-inducing assays and an rgg deletion mutant revealed that in S. mitis Rgg acts as an activator. Transcriptome analysis showed that in addition to shp, the system regulates two other downstream genes, comprising a segment of a putative lantibiotic gene cluster that is in a conjugative element locus in different members of the mitis group. Close comparison to a similar lantibiotic gene cluster in Streptococcus pneumoniae indicated that S. mitis lacked the full set of genes. Despite the potential of SHP to trigger a futile cycle of auto-induction, growth was not significantly affected for the rgg mutant under normal or antibiotic stress conditions. The S. mitis SHP was, however, fully functional in promoting cross-species communication and increasing S. pneumoniae surface polysaccharide production, which in this species is regulated by Rgg/SHP. The activity of SHPs produced by both species was detected in co-cultures using a S. mitis reporter strain. In competitive assays, a slight advantage was observed for the rgg mutants. We conclude that the Rgg/SHP system in S. mitis regulates the expression of its own shp, and activates an Rgg/SHP system in S. pneumoniae that regulates surface polysaccharide synthesis. Fundamentally, cross-communication of such systems may have a role during multi-species interactions.IMPORTANCEBacteria secrete signal molecules into the environment which are sensed by other cells when the density reaches a certain threshold. In this study, we describe a communication system in Streptococcus mitis, a commensal species from the oral cavity, which we also found in several species and strains of streptococci from the mitis group. Further, we show that this system can promote cross-communication with S. pneumoniae, a closely-related major human pathogen. Importantly, we show that this cross-communication can take place during co-culture. While the genes regulated in S. mitis are likely part of a futile cycle of activation, the target genes in S. pneumoniae are potentially involved in virulence. The understanding of such complex communication networks can provide important insights into the dynamics of bacterial communities.

RevDate: 2018-11-01

Schooley RT (2018)

The human microbiome: implications for health and disease, including HIV infection.

Topics in antiviral medicine, 26(3):75-78.

Our increased understanding of the human microbiome has brought insight into the role it plays in health and disease, including HIV infection. Studies have shown that the gut microbiome is less diverse in individuals with HIV infection than in noninfected control subjects. Efforts to modify the microbiome to bolster immune reconstitution in people with HIV infection have so far been unsuccessful. The vaginal microbiome affects risk of HIV acquisition, with Lactobacillus dominance being protective compared with vaginosis characterized by larger populations of Gardnerella. The vaginal microbiome might also affect efficacy of topical tenofovir disoproxil fumarate preexposure prophylaxis. This article summarizes a presentation by Robert T. Schooley, MD, at the IAS-USA continuing education program held in San Francisco in May 2018.

RevDate: 2018-11-16

Franzosa EA, McIver LJ, Rahnavard G, et al (2018)

Species-level functional profiling of metagenomes and metatranscriptomes.

Nature methods, 15(11):962-968.

Functional profiles of microbial communities are typically generated using comprehensive metagenomic or metatranscriptomic sequence read searches, which are time-consuming, prone to spurious mapping, and often limited to community-level quantification. We developed HUMAnN2, a tiered search strategy that enables fast, accurate, and species-resolved functional profiling of host-associated and environmental communities. HUMAnN2 identifies a community's known species, aligns reads to their pangenomes, performs translated search on unclassified reads, and finally quantifies gene families and pathways. Relative to pure translated search, HUMAnN2 is faster and produces more accurate gene family profiles. We applied HUMAnN2 to study clinal variation in marine metabolism, ecological contribution patterns among human microbiome pathways, variation in species' genomic versus transcriptional contributions, and strain profiling. Further, we introduce 'contributional diversity' to explain patterns of ecological assembly across different microbial community types.

RevDate: 2018-10-30

Vinberg M, Ottesen NM, Meluken I, et al (2018)

Remitted affective disorders and high familial risk of affective disorders associate with aberrant intestinal microbiota.

Acta psychiatrica Scandinavica [Epub ahead of print].

OBJECTIVE: Affective disorders seem associated with aberrant intestinal microbiota but whether this pattern also occurs in individuals at increased heritable risk is unknown. We investigated associations between gut microbiota profiles and affective disorders by comparing monozygotic (MZ) twins concordant (affected twins with unipolar or bipolar disorder in remission) and discordant to affective disorders (high-risk) with MZ twins without affective disorders (low-risk).

METHODS: Stool samples were collected from 128 MZ twins and the microbiome was profiled using 16S rDNA sequencing of the V3-V4 region.

RESULTS: Affected twins had a lower diversity and an absence of a specific operational taxonomical unit (OTU) in comparison with low-risk twins. The high-risk twins exhibited the same pattern although the lower diversity was only at a trend level. The OTU belonged to the family Christensenellaceae. The findings were not explained by lifestyle factors (smoking, alcohol consumption, body mass index, or psychotropic medication).

CONCLUSION: Affected twins in remission and high-risk twins presented aberrant gut microbiota with depletion of a specific OTU. If replicated, this reduced relative sequence absence may together with the globally altered microbiota composition act as a vulnerability marker by accentuating the effect of gene-environment interactions in individuals genetically disposed for an affective disorder.

RevDate: 2018-10-30

Pretzl B, Sälzer S, Ehmke B, et al (2018)

Administration of systemic antibiotics during non-surgical periodontal therapy-a consensus report.

Clinical oral investigations pii:10.1007/s00784-018-2727-0 [Epub ahead of print].

AIM: The aim of this meta-review was to evaluate whether there is a meaningful clinical benefit regarding the use of systemic adjunctive antibiotics in the treatment of patients with periodontitis. Additionally, a consensus regarding possible recommendations for future administration of antibiotics should be reached.

METHODS: A structured literature search was performed by two independent investigators focusing on systematic reviews (SR) covering adjunctive systemic antibiosis during non-surgical periodontal therapy. Additionally, recent randomized clinical trials (RCT, July 2015 to July 2017) were searched systematically to update the latest SR. Results were summarized and discussed in a plenary to reach a consensus.

RESULTS: Mostly, systematic reviews and RCTs showed a significant positive effect of adjunctive systematic antibiosis compared to controls. These positive effects gain clinical relevance in patients with severe periodontal disease aged 55 years and younger.

CONCLUSION: Systemic antibiotics as an adjunct to non-surgical periodontal therapy should be sensibly administered and restrictively used. Only certain groups of periodontitis patients show a significant and clinically relevant benefit after intake of systemic antibiosis during periodontal therapy.

CLINICAL RELEVANCE: Avoiding antibiotic resistance and possible side effects on the human microbiome should be a focus of dentists and physicians. Thus, a sensible administration of antibiotics is mandatory. This manuscript suggests guidelines for a reasonable use.

RevDate: 2018-11-14

Shi JY, Huang H, Zhang YN, et al (2018)

BMCMDA: a novel model for predicting human microbe-disease associations via binary matrix completion.

BMC bioinformatics, 19(Suppl 9):281 pii:10.1186/s12859-018-2274-3.

BACKGROUND: Human Microbiome Project reveals the significant mutualistic influence between human body and microbes living in it. Such an influence lead to an interesting phenomenon that many noninfectious diseases are closely associated with diverse microbes. However, the identification of microbe-noninfectious disease associations (MDAs) is still a challenging task, because of both the high cost and the limitation of microbe cultivation. Thus, there is a need to develop fast approaches to screen potential MDAs. The growing number of validated MDAs enables us to meet the demand in a new insight. Computational approaches, especially machine learning, are promising to predict MDA candidates rapidly among a large number of microbe-disease pairs with the advantage of no limitation on microbe cultivation. Nevertheless, a few computational efforts at predicting MDAs are made so far.

RESULTS: In this paper, grouping a set of MDAs into a binary MDA matrix, we propose a novel predictive approach (BMCMDA) based on Binary Matrix Completion to predict potential MDAs. The proposed BMCMDA assumes that the incomplete observed MDA matrix is the summation of a latent parameterizing matrix and a noising matrix. It also assumes that the independently occurring subscripts of observed entries in the MDA matrix follows a binomial model. Adopting a standard mean-zero Gaussian distribution for the nosing matrix, we model the relationship between the parameterizing matrix and the MDA matrix under the observed microbe-disease pairs as a probit regression. With the recovered parameterizing matrix, BMCMDA deduces how likely a microbe would be associated with a particular disease. In the experiment under leave-one-out cross-validation, it exhibits the inspiring performance (AUC = 0.906, AUPR =0.526) and demonstrates its superiority by ~ 7% and ~ 5% improvements in terms of AUC and AUPR respectively in the comparison with the pioneering approach KATZHMDA.

CONCLUSIONS: Our BMCMDA provides an effective approach for predicting MDAs and can be also extended to other similar predicting tasks of binary relationship (e.g. protein-protein interaction, drug-target interaction).

RevDate: 2018-10-25

Vatanen T, Franzosa EA, Schwager R, et al (2018)

The human gut microbiome in early-onset type 1 diabetes from the TEDDY study.

Nature, 562(7728):589-594.

Type 1 diabetes (T1D) is an autoimmune disease that targets pancreatic islet beta cells and incorporates genetic and environmental factors1, including complex genetic elements2, patient exposures3 and the gut microbiome4. Viral infections5 and broader gut dysbioses6 have been identified as potential causes or contributing factors; however, human studies have not yet identified microbial compositional or functional triggers that are predictive of islet autoimmunity or T1D. Here we analyse 10,913 metagenomes in stool samples from 783 mostly white, non-Hispanic children. The samples were collected monthly from three months of age until the clinical end point (islet autoimmunity or T1D) in the The Environmental Determinants of Diabetes in the Young (TEDDY) study, to characterize the natural history of the early gut microbiome in connection to islet autoimmunity, T1D diagnosis, and other common early life events such as antibiotic treatments and probiotics. The microbiomes of control children contained more genes that were related to fermentation and the biosynthesis of short-chain fatty acids, but these were not consistently associated with particular taxa across geographically diverse clinical centres, suggesting that microbial factors associated with T1D are taxonomically diffuse but functionally more coherent. When we investigated the broader establishment and development of the infant microbiome, both taxonomic and functional profiles were dynamic and highly individualized, and dominated in the first year of life by one of three largely exclusive Bifidobacterium species (B. bifidum, B. breve or B. longum) or by the phylum Proteobacteria. In particular, the strain-specific carriage of genes for the utilization of human milk oligosaccharide within a subset of B. longum was present specifically in breast-fed infants. These analyses of TEDDY gut metagenomes provide, to our knowledge, the largest and most detailed longitudinal functional profile of the developing gut microbiome in relation to islet autoimmunity, T1D and other early childhood events. Together with existing evidence from human cohorts7,8 and a T1D mouse model9, these data support the protective effects of short-chain fatty acids in early-onset human T1D.

RevDate: 2018-11-14

Tackmann J, Arora N, Schmidt TSB, et al (2018)

Ecologically informed microbial biomarkers and accurate classification of mixed and unmixed samples in an extensive cross-study of human body sites.

Microbiome, 6(1):192 pii:10.1186/s40168-018-0565-6.

BACKGROUND: The identification of body site-specific microbial biomarkers and their use for classification tasks have promising applications in medicine, microbial ecology, and forensics. Previous studies have characterized site-specific microbiota and shown that sample origin can be accurately predicted by microbial content. However, these studies were usually restricted to single datasets with consistent experimental methods and conditions, as well as comparatively small sample numbers. The effects of study-specific biases and statistical power on classification performance and biomarker identification thus remain poorly understood. Furthermore, reliable detection in mixtures of different body sites or with noise from environmental contamination has rarely been investigated thus far. Finally, the impact of ecological associations between microbes on biomarker discovery was usually not considered in previous work.

RESULTS: Here we present the analysis of one of the largest cross-study sequencing datasets of microbial communities from human body sites (15,082 samples from 57 publicly available studies). We show that training a Random Forest Classifier on this aggregated dataset increases prediction performance for body sites by 35% compared to a single-study classifier. Using simulated datasets, we further demonstrate that the source of different microbial contributions in mixtures of different body sites or with soil can be detected starting at 1% of the total microbial community. We apply a biomarker selection method that excludes indirect environmental associations driven by microbe-microbe associations, yielding a parsimonious set of highly predictive taxa including novel biomarkers and excluding many previously reported taxa. We find a considerable fraction of unclassified biomarkers ("microbial dark matter") and observe that negatively associated taxa have a surprisingly high impact on classification performance. We further detect a significant enrichment of rod-shaped, motile, and sporulating taxa for feces biomarkers, consistent with a highly competitive environment.

CONCLUSIONS: Our machine learning model shows strong body site classification performance, both in single-source samples and mixtures, making it promising for tasks requiring high accuracy, such as forensic applications. We report a core set of ecologically informed biomarkers, inferred across a wide range of experimental protocols and conditions, providing the most concise, general, and least biased overview of body site-associated microbes to date.

RevDate: 2018-11-14

Benler S, Cobián-Güemes AG, McNair K, et al (2018)

A diversity-generating retroelement encoded by a globally ubiquitous Bacteroides phage.

Microbiome, 6(1):191 pii:10.1186/s40168-018-0573-6.

BACKGROUND: Diversity-generating retroelements (DGRs) are genetic cassettes that selectively mutate target genes to produce hypervariable proteins. First characterized in Bordetella bacteriophage BPP-1, the DGR creates a hypervariable phage tail fiber that enables host tropism switching. Subsequent surveys for DGRs conclude that the majority identified to date are bacterial or archaeal in origin. This work examines bacteriophage and bacterial genomes for novel phage-encoded DGRs.

RESULTS: This survey discovered 92 DGRs that were only found in phages exhibiting a temperate lifestyle. The majority of phage-encoded DGRs were identified as prophages in bacterial hosts from the phyla Bacteroidetes, Proteobacteria, and Firmicutes. Sequence reads from these previously unidentified prophages were present in viral metagenomes (viromes), indicating these prophages can produce functional viruses. Five phages possessed hypervariable proteins with structural similarity to the tail fiber of BPP-1, whereas the functions of the remaining DGR target proteins were unknown. A novel temperate phage that harbors a DGR cassette targeting a protein of unknown function was induced from Bacteroides dorei. This phage, here named Bacteroides dorei Hankyphage, lysogenizes 13 different Bacteroides species and was present in 34% and 21% of whole-community metagenomes and human-associated viromes, respectively.

CONCLUSIONS: Here, the number of known DGR-containing phages is increased from four to 92. All of these phages exhibit a temperate lifestyle, including a cosmopolitan human-associated phage. Targeted hypervariation by temperate phages may be a ubiquitous mechanism underlying phage-bacteria interaction in the human microbiome.

RevDate: 2018-11-14

Chaudhari NM, Gautam A, Gupta VK, et al (2018)

PanGFR-HM: A Dynamic Web Resource for Pan-Genomic and Functional Profiling of Human Microbiome With Comparative Features.

Frontiers in microbiology, 9:2322.

The conglomerate of microorganisms inhabiting various body-sites of human, known as the human microbiome, is one of the key determinants of human health and disease. Comprehensive pan-genomic and functional analysis approach for human microbiome components can enrich our understanding about impact of microbiome on human health. By utilizing this approach we developed PanGFR-HM (http://www.bioinfo.iicb.res.in/pangfr-hm/) - a novel dynamic web-resource that integrates genomic and functional characteristics of 1293 complete microbial genomes available from Human Microbiome Project. The resource allows users to explore genomic/functional diversity and genome-based phylogenetic relationships between human associated microbial genomes, not provided by any other resource. The key features implemented here include pan-genome and functional analysis of organisms based on taxonomy or body-site, and comparative analysis between groups of organisms. The first feature can also identify probable gene-loss events and significantly over/under represented KEGG/COG categories within pan-genome. The unique second feature can perform comparative genomic, functional and pathways analysis between 4 groups of microbes. The dynamic nature of this resource enables users to define parameters for orthologous clustering and to select any set of organisms for analysis. As an application for comparative feature of PanGFR-HM, we performed a comparative analysis with 67 Lactobacillus genomes isolated from human gut, oral cavity and urogenital tract, and therefore characterized the body-site specific genes, enzymes and pathways. Altogether, PanGFR-HM, being unique in its content and functionality, is expected to provide a platform for microbiome-based comparative functional and evolutionary genomics.

RevDate: 2018-11-14

Chen Z, Yeoh YK, Hui M, et al (2018)

Diversity of macaque microbiota compared to the human counterparts.

Scientific reports, 8(1):15573 pii:10.1038/s41598-018-33950-6.

Studies on the microbial communities in non-human primate hosts provide unique insights in both evolution and function of microbes related to human health and diseases. Using 16S rRNA gene amplicon profiling, we examined the oral, anal and vaginal microbiota in a group of non-captive rhesus macaques (N = 116) and compared the compositions with the healthy communities from Human Microbiome Project. The macaque microbiota was dominated by Bacteroidetes, Firmicutes and Proteobacteria; however, there were marked differences in phylotypes enriched across body sites indicative of strong niche specialization. Compared to human gut microbiota where Bacteroides predominately enriched, the surveyed macaque anal community exhibited increased abundance of Prevotella. In contrast to the conserved human vaginal microbiota extremely dominated by Lactobacillus, the macaque vaginal microbial composition was highly diverse while lactobacilli were rare. A constant decrease of the vaginal microbiota diversity was observed among macaque samples from juvenile, adult without tubectomy, and adult with tubectomy, with the most notable distinction being the enrichment of Halomonas in juvenile and Saccharofermentans in contracepted adults. Both macaque and human oral microbiota were colonized with three most common oral bacterial genera: Streptococcus, Haemophilus and Veillonella, and shared relatively conserved communities to each other. A number of bacteria related to human pathogens were consistently detected in macaques. The findings delineate the range of structure and diversity of microbial communities in a wild macaque population, and enable the application of macaque as an animal model for future characterization of microbes in transmission, genomics and function.

RevDate: 2018-11-29

Ponziani FR, Putignani L, Paroni Sterbini F, et al (2018)

Influence of hepatitis C virus eradication with direct-acting antivirals on the gut microbiota in patients with cirrhosis.

Alimentary pharmacology & therapeutics, 48(11-12):1301-1311.

BACKGROUND: The cure of hepatitis C virus (HCV) infection may contribute to the reduction of liver fibrosis progression and potentially influence the gut-liver axis.

AIM: To investigate the influence of HCV infection eradication with direct-acting antivirals (DAAs) on the gut microbiota composition as well as on intestinal and systemic inflammatory parameters in patients with cirrhosis.

METHODS: Consecutive patients with HCV-related cirrhosis receiving DAA treatment were included. The gut microbiota composition, intestinal permeability, and inflammation were assessed before treatment and after 1 year. Clinical outcomes such as episodes of decompensation and markers of liver fibrosis were evaluated over a 2-year follow-up period.

RESULTS: The gut microbiota alpha diversity in cirrhotic patients, which was lower than that in healthy subjects, was significantly improved by the cure of HCV infection and a shift in the overall gut microbiota composition was observed compared to baseline. The abundance of potentially pathogenic bacteria (Enterobacteriaceae, Enterococcus, and Staphylococcus) was decreased after treatment. The gut microbiota composition was associated with the inflammatory profile and markers of liver fibrosis. Although a significant reduction in the serum levels of cytokines and chemokines was observed post-DAA treatment, measures of intestinal permeability and inflammation remained unchanged.

CONCLUSIONS: Cure of HCV infection with DAAs in patients with cirrhosis is associated with a modification of the gut microbiota, which correlates with fibrosis and inflammation but does not improve intestinal barrier function.

RevDate: 2018-11-14

Duran-Pinedo AE, Solbiati J, J Frias-Lopez (2018)

The effect of the stress hormone cortisol on the metatranscriptome of the oral microbiome.

NPJ biofilms and microbiomes, 4:25 pii:68.

Imbalances of the microbiome, also referred to as microbial dysbiosis, could lead to a series of different diseases. One factor that has been shown to lead to dysbiosis of the microbiome is exposure to psychological stressors. Throughout evolution microorganisms of the human microbiome have developed systems for sensing host-associated signals such as hormones associated with those stressors, enabling them to recognize essential changes in their environment, thus changing their expression gene profile to fit the needs of the new environment. The most widely accepted theory explaining the ability of hormones to affect the outcome of an infection involves the suppression of the immune system. Commensal microbiota is involved in stressor-induced immunomodulation, but other biological effects are not yet known. Here we present the impact that cortisol had on the community-wide transcriptome of the oral community. We used a metatranscriptomic approach to obtain first insights into the metabolic changes induced by this stress hormone as well as which members of the oral microbiome respond to the presence of cortisol in the environment. Our findings show that the stress hormone cortisol directly induces shifts in the gene expression profiles of the oral microbiome that reproduce results found in the profiles of expression of periodontal disease and its progression.

RevDate: 2018-11-30

Chen B, Wang J, Wang Y, et al (2018)

Oral microbiota dysbiosis and its association with Henoch-Schönlein Purpura in children.

International immunopharmacology, 65:295-302.

BACKGROUND: The pathogenesis of microbes in allergic diseases has been demonstrated and our previous research indicates that microbiota causing gut disorders in children is associated with Henoch-Schönlein Purpura. However, the role of oral microbiota in Henoch-Schönlein Purpura remains unknown.

METHOD: A total of 164 children were enrolled, of which 98 were patients with HSP and 66 were healthy children. Oral swab samples were collected for DNA extraction and 16S rRNA gene sequencing, then analyzed for oral microbiota composition.

RESULTS: Oral microbiota differed between healthy children and those with HSP. Children with HSP exhibited higher oral microbial diversity and richness than the controls. Firmicutes, Proteobacteria, and Bacteroidetes are the dominant phyla in children with HSP. We used linear discriminant analysis (LDA) effect size (LEfSe) algorithm and detected 21 bacterial taxonomic clades showing statistical differences (12 increased and 9 decreased) in children with HSP. The correlation analyses between clinical data and abundance in microbial community indicated that an abundance of Butyrivibrio sp. negatively correlated with the length of hospital stay (LOS). Haemophilus sp. negatively correlated to IgE and IgM but positively correlated to LOS, with decreasing significantly in patients with HSP. Prevotella positively correlated with IgM. Prevotella nanceiensis positively correlated with IgA, and were abundant in children with HSP.

CONCLUSIONS: These results indicate that children with HSP have significantly different oral microbiota compared to healthy children. Although this study does not imply causality, it is helpful to identify the types and pathways of bacteria that can be used to prevent or treat HSP.

RevDate: 2018-11-14

Wyman SK, Avila-Herrera A, Nayfach S, et al (2018)

A most wanted list of conserved microbial protein families with no known domains.

PloS one, 13(10):e0205749 pii:PONE-D-18-08043.

The number and proportion of genes with no known function are growing rapidly. To quantify this phenomenon and provide criteria for prioritizing genes for functional characterization, we developed a bioinformatics pipeline that identifies robustly defined protein families with no annotated domains, ranks these with respect to phylogenetic breadth, and identifies them in metagenomics data. We applied this approach to 271 965 protein families from the SFams database and discovered many with no functional annotation, including >118 000 families lacking any known protein domain. From these, we prioritized 6 668 conserved protein families with at least three sequences from organisms in at least two distinct classes. These Function Unknown Families (FUnkFams) are present in Tara Oceans Expedition and Human Microbiome Project metagenomes, with distributions associated with sampling environment. Our findings highlight the extent of functional novelty in sequence databases and establish an approach for creating a "most wanted" list of genes to prioritize for further characterization.

RevDate: 2018-10-16

Waterhouse M, Hope B, Krause L, et al (2018)

Vitamin D and the gut microbiome: a systematic review of in vivo studies.

European journal of nutrition pii:10.1007/s00394-018-1842-7 [Epub ahead of print].

PURPOSE: Variation in the human microbiome has been linked with a variety of physiological functions, including immune regulation and metabolism and biosynthesis of vitamins, hormones, and neurotransmitters. Evidence for extraskeletal effects of vitamin D has been accruing and it has been suggested that the effect of vitamin D on health is partially mediated through the microbiome. We aimed to critically evaluate the evidence linking vitamin D and the gastrointestinal microbiome.

METHODS: We systematically searched the Embase, Web of Science, PubMed and CINAHL databases, including peer-reviewed publications that reported an association between a measure of vitamin D and the gastrointestinal microbiome in humans or experimental animals.

RESULTS: We included 10 mouse and 14 human studies. Mouse studies compared mice fed diets containing different levels of vitamin D (usually high versus low), or vitamin D receptor knockout or Cyp27B1 knockout with wild-type mice. Five mouse studies reported an increase in Bacteroidetes (or taxa within that phylum) in the low vitamin D diet or gene knockout group. Human studies were predominantly observational; all but two of the included studies found some association between vitamin D and the gut microbiome, but the nature of differences observed varied across studies.

CONCLUSIONS: Despite substantial heterogeneity, we found evidence to support the hypothesis that vitamin D influences the composition of the gastrointestinal microbiome. However, the research is limited, having been conducted either in mice or in mostly small, selected human populations. Future research in larger population-based studies is needed to fully understand the extent to which vitamin D modulates the microbiome.

RevDate: 2018-10-12

Bilen M, Mbogning Fonkou MD, Khelaifia S, et al (2018)

Taxonogenomics description of Parabacteroides timonensis sp. nov. isolated from a human stool sample.

MicrobiologyOpen [Epub ahead of print].

Intensive efforts have been made to describe the human microbiome and its involvement in health and disease. Culturomics has been recently adapted to target formerly uncultured bacteria and other unclassified bacterial species. This approach enabled us to isolate in the current study a new bacterial species, Parabacteroides timonensis strain Marseille-P3236T , from a stool sample of a healthy 39-year-old pygmy male. This strain, is an anaerobic, gram-negative, nonspore-forming motile rod. Its genome is made up of 6,483,434 bp with 43.41% G+C content, 5046 protein-encoding genes, and 84 RNA genes. We herein provide the full description of Parabacteroides timonensis strain Marseille-P3236T through the taxonogenomic approach.

RevDate: 2018-10-10

Balato A, Cacciapuoti S, Di Caprio R, et al (2018)

Human Microbiome: Composition and Role in Inflammatory Skin Diseases.

Archivum immunologiae et therapiae experimentalis pii:10.1007/s00005-018-0528-4 [Epub ahead of print].

This review focuses on recent evidences about human microbiome composition and functions, exploring the potential implication of its impairment in some diffuse and invalidating inflammatory skin diseases, such as atopic dermatitis, psoriasis, hidradenitis suppurativa and acne. We analysed current scientific literature, focusing on the current evidences about gut and skin microbiome composition and the complex dialogue between microbes and the host. Finally, we examined the consequences of this dialogue for health and skin diseases. This review highlights how human microbes interact with different anatomic niches modifying the state of immune activation, skin barrier status, microbe-host and microbe-microbe interactions. It also shows as most of the factors affecting gut and skin microorganisms' activity have demonstrated to be effective also in modulating chronic inflammatory skin diseases. More and more evidences demonstrate that human microbiome plays a key role in human health and diseases. It is to be expected that these new insights will translate into diagnostic, therapeutic and preventive measures in the context of personalized/precision medicine.

RevDate: 2018-10-09

Bell JS, Spencer JI, Yates RL, et al (2018)

From Nose to Gut - The Role of the Microbiome in Neurological Disease.

Neuropathology and applied neurobiology [Epub ahead of print].

Inflammation and neurodegeneration are key features of many chronic neurological diseases, yet the causative mechanisms underlying these processes are poorly understood. There has been mounting interest in the role of the human microbiome in modulating the inflammatory milieu of the central nervous system in health and disease. To date, most research has focussed on a gut-brain axis, with other mucosal surfaces being relatively neglected. We herein take the novel approach of comprehensively reviewing the roles of the microbiome across several key mucosal interfaces - the nose, mouth, lung, and gut - in health and in Parkinson's disease (PD), Alzheimer's disease (AD) and multiple sclerosis (MS). This review systematically appraises the anatomical and microbiological landscape of each mucosal surface in health and disease before considering relevant mechanisms that may influence the initiation and progression of PD, AD, and MS. The cumulative effects of dysbiosis from the nose to the gut may contribute significantly to neurological disease through a wide variety of mechanisms, including direct translocation of bacteria and their products, and modulation of systemic or central nervous system-specific immunity. This remains an understudied and exciting area for future research and may lead to the development of therapeutic targets for chronic neurological disease. This article is protected by copyright. All rights reserved.

RevDate: 2018-10-09

Macklaim JM, GB Gloor (2018)

From RNA-seq to Biological Inference: Using Compositional Data Analysis in Meta-Transcriptomics.

Methods in molecular biology (Clifton, N.J.), 1849:193-213.

The proper analysis of high-throughput sequencing datasets of mixed microbial communities (meta-transcriptomics) is substantially more complex than for datasets composed of single organisms. Adapting commonly used RNA-seq methods to the analysis of meta-transcriptome datasets can be misleading and not use all the available information in a consistent manner. However, meta-transcriptomic experiments can be investigated in a principled manner using Bayesian probabilistic modeling of the data at a functional level coupled with analysis under a compositional data analysis paradigm. We present a worked example for the differential functional evaluation of mixed-species microbial communities obtained from human clinical samples that were sequenced on an Illumina platform. We demonstrate methods to functionally map reads directly, conduct a compositionally appropriate exploratory data analysis, evaluate differential relative abundance, and finally identify compositionally associated (constant ratio) functions. Using these approaches we have found that meta-transcriptomic functional analyses are highly reproducible and convey significant information regarding the ecosystem.

RevDate: 2018-11-14

Hoggard M, Vesty A, Wong G, et al (2018)

Characterizing the Human Mycobiota: A Comparison of Small Subunit rRNA, ITS1, ITS2, and Large Subunit rRNA Genomic Targets.

Frontiers in microbiology, 9:2208.

Interest in the human microbiome has increased dramatically in the last decade. However, much of this research has focused on bacteria, while the composition and roles of their fungal counterparts remain less understood. Furthermore, a variety of methodological approaches have been applied, and the comparability between studies is unclear. This study compared four primer pairs targeting the small subunit (SSU) rRNA (18S), ITS1, ITS2, and large subunit (LSU) rRNA (26S) genomic regions for their ability to accurately characterize fungal communities typical of the human mycobiota. All four target regions of 21 individual fungal mock community taxa were capable of being amplified adequately and sequenced. Mixed mock community analyses revealed marked variability in the ability of each primer pair to accurately characterize a complex community. ITS target regions outperformed LSU and SSU. Of the ITS regions, ITS1 failed to generate sequences for Yarrowia lipolytica and all three Malassezia species when in a mixed community. These findings were further supported in studies of human sinonasal and mouse fecal samples. Based on these analyses, previous studies using ITS1, SSU, or LSU markers may omit key taxa that are identified by the ITS2 marker. Of methods commonly used in human mycobiota studies to date, we recommend selection of the ITS2 marker. Further investigation of more recently developed fungal primer options will be essential to ultimately determine the optimal methodological approach by which future human mycobiota studies ought to be standardized.

RevDate: 2018-10-23

Romano L, Gualtieri P, Nicoletti F, et al (2018)

Neurodegenerative disorders, gut human microbiome and diet: future research for prevention and supportive therapies.

European review for medical and pharmacological sciences, 22(18):5771-5772.

RevDate: 2018-10-02

Vamanu E (2018)

Complementary functional strategy for modulation of human gut microbiota.

Current pharmaceutical design pii:CPD-EPUB-93334 [Epub ahead of print].

BACKGROUND: Two pathologies commonly associated with gut microbiota dysbiosis are type 2 diabetes and cardiovascular diseases. A disturbance in microbial balance translates into the occurrence of degenerative dysfunctions that are also associated with other pathologies, such as obesity, colon cancer.

METHODS: Thus, the aim of this review was to present the significant findings related to human microbiome modulation via the prebiotic effects of wild edible mushrooms as a complementary strategy to modern treatment.

RESULTS: Since diet and medication are two important causes of microbiome fingerprint modifications, new complementary and alternative methods can include wild edible mushrooms, which serve as functional products, given their properties in modulating the microbial pattern at the colon level. The metagenomic study has enabled the identification of some competitive microbiological and biochemical biomarkers which allow the development of innovative strategies in controlling microbial disbalance from human gut.

CONCLUSION: Certain mushroom species have been approaching and their effects on the microbiota fingerprint of two major target groups are highlighted.

RevDate: 2018-10-02

Perkins RC (2019)

Making the Case for Functional Proteomics.

Methods in molecular biology (Clifton, N.J.), 1871:1-40.

"Making the Case for Functional Proteomics" first differentiates the Functional Proteome from the products of genetic protein expression. Qualitatively, the prevalence of posttranslational modifications (PTMs) virtually insures that individual, functional proteins do not equate to their genetic expression counterparts. Quantitatively, considering the frequency of PTMs and a conservative estimate of the number of functional entities arising from protein interactions, the size of the Functional Proteome exceeds that of the human genome by at least two orders of magnitude. The human genome does not, cannot, map the Functional Proteome. Further, the collective genome of the human microbiome dwarfs the human genome. With these facts established, "Making the Case…" proceeds to examine Functional Proteomics (of which both "gene expression" and "epigenetics" are but parts of a larger whole) within the context of Systems Biology, concluding that functionally related networks comprise the dominant motif for biological activity. Creating just such a network focus is essential in not only expanding basic knowledge but also in applying that knowledge in the pragmatic efforts of drug and biomarker development. Outlines for development of drugs and biomarkers, as well as the realization of precision medicine, within a functional proteomics-based, network motif are provided. The chapter proceeds to asses both the knowledge base and the tools to fully embrace Functional Proteomics. Given the decades-long infatuation with the reductionism of genomics, it is not surprising that both the proteomics knowledge base and tools are assessed as poor to fair. However, even a minor shift in research funding and a renewed challenge to methods developers will rapidly improve the current situation. Adoption of the included "Roadmap" will realistically make the twenty-first century the century of a long-awaited revolution in biology.

RevDate: 2018-11-16

Gonzalez A, Navas-Molina JA, Kosciolek T, et al (2018)

Qiita: rapid, web-enabled microbiome meta-analysis.

Nature methods, 15(10):796-798.

Multi-omic insights into microbiome function and composition typically advance one study at a time. However, in order for relationships across studies to be fully understood, data must be aggregated into meta-analyses. This makes it possible to generate new hypotheses by finding features that are reproducible across biospecimens and data layers. Qiita dramatically accelerates such integration tasks in a web-based microbiome-comparison platform, which we demonstrate with Human Microbiome Project and Integrative Human Microbiome Project (iHMP) data.

RevDate: 2018-10-26
CmpDate: 2018-10-26

Aziz RK, Hegazy SM, Yasser R, et al (2018)

Drug pharmacomicrobiomics and toxicomicrobiomics: from scattered reports to systematic studies of drug-microbiome interactions.

Expert opinion on drug metabolism & toxicology, 14(10):1043-1055.

INTRODUCTION: Pharmacomicrobiomics and toxicomicrobiomics study how variations within the human microbiome (the combination of human-associated microbial communities and their genomes) affect drug disposition, action, and toxicity. These emerging fields, interconnecting microbiology, bioinformatics, systems pharmacology, and toxicology, complement pharmacogenomics and toxicogenomics, expanding the scope of precision medicine. Areas covered: This article reviews some of the most recently reported pharmacomicrobiomic and toxicomicrobiomic interactions. Examples include the impact of the human gut microbiota on cardiovascular drugs, natural products, and chemotherapeutic agents, including immune checkpoint inhibitors. Although the gut microbiota has been the most extensively studied, some key drug-microbiome interactions involve vaginal, intratumoral, and environmental bacteria, and are briefly discussed here. Additionally, computational resources, moving the field from cataloging to predicting interactions, are introduced. Expert opinion: The rapid pace of discovery triggered by the Human Microbiome Project is moving pharmacomicrobiomic research from scattered observations to systematic studies focusing on screening microbiome variants against different drug classes. Better representation of all human populations will improve such studies by avoiding sampling bias, and the integration of multiomic studies with designed experiments will allow establishing causation. In the near future, pharmacomicrobiomic testing is expected to be a key step in screening novel drugs and designing precision therapeutics.

RevDate: 2018-11-28

Hattori M (2018)

[Ecology and function of human microbiomes.].

Clinical calcium, 28(10):1398-1405.

Hundreds of trillions of bacteria consisting of ~1,000 species reside in various human body sites to form bacterial communities(microbiomes)specific for the sites. In the past decade, the human microbiome research in the world incredibly advanced by development of a culture-independent metagenomic analysis based on next-generation sequencing technologies. Particularly, current studies have revealed that the human gut microbiome is profoundly associated with the host's health and disease.

RevDate: 2018-11-14

Maleki Vareki S, Chanyi RM, Abdur-Rashid K, et al (2018)

Moving on from Metchnikoff: thinking about microbiome therapeutics in cancer.

Ecancermedicalscience, 12:867 pii:can-12-867.

Precision medicine now needs to also consider the microbiome in oncology treatment. Ingested substances, whether they are a carcinogenic or therapeutic agent, will likely come into contact with the microbiota. Even those delivered extra-intestinally can be influenced beyond xenobiotic metabolism by biochemical factors associated with the microbiota or by an immunological predisposition created by the microbiome. We need to undertake one of the largest paradigm shifts to ever occur in medicine, that is, every drug or ingested substance needs to be re-evaluated for its pharmacological effect post-microbiome interaction. The importance of the microbiome with a focus on the treatment of cancer is discussed. In the near future, it may be possible to specifically manipulate the microbial composition within cancer patients to improve the therapeutic potential of existing oncological agents. However, the current tools to do so are limited. Targeted modulation is likely to be achieved by addition, selective enhancement or depletion of specific microbial types. This may include compounds such as narrow spectrum antimicrobial agents or oligosaccharides that will kill or enhance the bacterial growth of distinct members of the microbiota, respectively. This will stimulate a new era in these fields.

RevDate: 2018-09-27

Munson E, KC Carroll (2018)

An Update on the Novel Genera and Species and Revised Taxonomic Status of Bacterial Organisms Described in 2016 and 2017.

Journal of clinical microbiology pii:JCM.01181-18 [Epub ahead of print].

Recognition and acknowledgment of novel bacterial taxonomy and nomenclature revisions can impact clinical practice, disease epidemiology, and routine clinical microbiology laboratory operations. The Journal of Clinical Microbiology (JCM) herein presents its biannual report summarizing such changes published in the years 2016 and 2017, as published and added by the International Journal of Systematic and Evolutionary Microbiology Noteworthy discussion centers around descriptions of novel Corynebacteriaceae and an anaerobic mycolic-acid-producing bacterium in the suborder Corynebacterineae; revisions within the Propionibacterium, Clostridium, Borrelia, and Enterobacter genera; and, a major reorganization of the family EnterobacteriaceaeJCM intends to sustain this series of reports as advancements in molecular genetics, whole genome sequencing, and studies of the human microbiome will continue to produce novel taxa and clearer understandings of bacterial relatedness.

RevDate: 2018-09-26

Nazaroff WW (2018)

Embracing microbes in exposure science.

Journal of exposure science & environmental epidemiology pii:10.1038/s41370-018-0075-4 [Epub ahead of print].

Although defined more broadly, exposure science has mainly focused on exposures to environmental chemicals and related stressors, such as airborne particulate matter. There is an opportunity for exposure science to contribute more substantially to improving public health by devoting more attention to microorganisms as key stressors and agents in exposure. The discovery that pathogenic microbes cause disease in humans precipitated a revolution in public health science and disease prevention. With a continued global urgency to address spread of pathogenic microbes, contributions of microorganisms to both infectious and noninfectious processes merit more attention from the exposure science community. Today, discoveries of the importance of the human microbiome as a determinant of health and disease are precipitating a second revolution. Emerging knowledge creates a major opportunity to expand the scope of exposure science to incorporate the human microbiome as a target and modulator of exposure. A study committee of the National Academies of Sciences, Engineering, and Medicine has defined a research strategy to address health risks that pertain to the interaction of environmental chemicals with the human microbiome. Some aspects of this strategy pose important challenges and opportunities for the exposure science community.

RevDate: 2018-11-14

Zhao Y, Chen B, Li S, et al (2018)

Detection and characterization of bacterial nucleic acids in culture-negative synovial tissue and fluid samples from rheumatoid arthritis or osteoarthritis patients.

Scientific reports, 8(1):14305 pii:10.1038/s41598-018-32675-w.

Human intestinal microbes can mediate development of arthritis - Studies indicate that certain bacterial nucleic acids may exist in synovial fluid (SF) and could be involved in arthritis, although the underlying mechanism remains unclear. To characterize potential SF bacterial nucleic acids, we used 16S rRNA gene amplicon sequencing to assess bacterial nucleic acid communities in 15 synovial tissue (ST) and 110 SF samples from 125 patients with rheumatoid arthritis (RA) and 16 ST and 42 SF samples from 58 patients with osteoarthritis (OA). Our results showed an abundant diversity of bacterial nucleic acids in these clinical samples, including presence of Porphyromonas and Bacteroides in all 183 samples. Agrobacterium, Comamonas, Kocuria, Meiothermus, and Rhodoplanes were more abundant in synovial tissues of rheumatoid arthritis (STRA). Atopobium, Phascolarctobacterium, Rhodotorula mucilaginosa, Bacteroides uniformis, Rothia, Megasphaera, Turicibacter, Leptotrichia, Haemophilus parainfluenzae, Bacteroides fragilis, Porphyromonas, and Streptococcus were more abundant in synovial tissues of osteoarthritis (STOA). Veillonella dispar, Haemophilus parainfluenzae, Prevotella copri and Treponema amylovorum were more abundant in synovial fluid of rheumatoid arthritis (SFRA), while Bacteroides caccae was more abundant in the synovial fluid of osteoarthritis (SFOA). Overall, this study confirms existence of bacterial nucleic acids in SF and ST samples of RA and OA lesions and reveals potential correlations with degree of disease.

RevDate: 2018-10-21

Wang N, Zhu F, Chen L, et al (2018)

Proteomics, metabolomics and metagenomics for type 2 diabetes and its complications.

Life sciences, 212:194-202.

Type 2 diabetes mellitus (T2DM) is one of the most common diseases of endocrine and metabolic disorders, whose mechanism is still largely unknown. Fortunately, various "omics" tools have been employed to better understand the progression pathologies of T2DM and its complications. More specifically, proteomics, metabolomics and metagenomics have played crucial roles in advancing deeper understanding of the physiological processes and regulatory mechanisms of T2DM, such as regulation of signaling pathways perturbed by glucose levels, intestinal microorganism, and inflammation and so on. By analyzing the dynamic change and modification of proteins, proteomics has become an important tool in biology and medicine. Metabolomic analysis can amplify and quantify metabolites in living organisms to reveal the relative relationship between metabolites and physiological and pathological changes. There are also increasing evidences that the human microbiome, specifically the gastrointestinal microbiome have a potential role in the etiology and pathological outcomes of T2DM and its complications. This article summarized and discussed the recent applications of these "omics" tools in finding biomarkers for T2DM and its complications. We also reviewed employing multiple "omics" to further advance our understanding of this pathology. This review will benefit deeper understanding in new therapeutic and/or diagnostic biological target for the discovery of T2DM and its complications.


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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E-mail: RJR8222@gmail.com

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

short personal version

Curriculum Vitae for R J Robbins

long standard version

RJR Picks from Around the Web (updated 11 MAY 2018 )