Did you mean: bacteroidetes
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Nutrients May 2020The gut microbiota is emerging as a promising target for the management or prevention of inflammatory and metabolic disorders in humans. Many of the current research... (Review)
Review
The gut microbiota is emerging as a promising target for the management or prevention of inflammatory and metabolic disorders in humans. Many of the current research efforts are focused on the identification of specific microbial signatures, more particularly for those associated with obesity, type 2 diabetes, and cardiovascular diseases. Some studies have described that the gut microbiota of obese animals and humans exhibits a higher Firmicutes/Bacteroidetes ratio compared with normal-weight individuals, proposing this ratio as an eventual biomarker. Accordingly, the Firmicutes/Bacteroidetes ratio is frequently cited in the scientific literature as a hallmark of obesity. The aim of the present review was to discuss the validity of this potential marker, based on the great amount of contradictory results reported in the literature. Such discrepancies might be explained by the existence of interpretative bias generated by methodological differences in sample processing and DNA sequence analysis, or by the generally poor characterization of the recruited subjects and, more particularly, the lack of consideration of lifestyle-associated factors known to affect microbiota composition and/or diversity. For these reasons, it is currently difficult to associate the Firmicutes/Bacteroidetes ratio with a determined health status and more specifically to consider it as a hallmark of obesity.
Topics: Adult; Aged; Bacteroidetes; Biomarkers; Colony Count, Microbial; Dysbiosis; Female; Firmicutes; Gastrointestinal Microbiome; Humans; Male; Middle Aged; Obesity; Reproducibility of Results; Sequence Analysis, DNA
PubMed: 32438689
DOI: 10.3390/nu12051474 -
Frontiers in Immunology 2020is a relatively new genus of bacteria isolated primarily from medical clinical samples, although at a low rate compared to other genus members of the phylum, which are... (Review)
Review
is a relatively new genus of bacteria isolated primarily from medical clinical samples, although at a low rate compared to other genus members of the phylum, which are highly relevant in dysbiosis and disease. According to the taxonomy database at The National Center for Biotechnology Information, the genus consists of 13 species: , and and , and the subspecies subspecies vulgaris (vs. subsp.) are the newest strains featured outside that list. Although typically isolated from the human gut microbiome various species of this genus have been isolated from patients suffering from appendicitis, and abdominal and rectal abscess. It is possible that as spp. emerge, their identification in clinical samples may be underrepresented as novel MS-TOF methods may not be fully capable to discriminate distinct species as separate since it will require the upgrading of MS-TOF identification databases. In terms of pathogenicity, there is contrasting evidence indicating that may have protective effects against some diseases, including liver fibrosis, colitis, cancer immunotherapy, and cardiovascular disease. In contrast, other studies indicate is pathogenic in colorectal cancer and is associated with mental signs of depression. Gut dysbiosis seems to play a role in determining the compositional abundance of in the feces (., in non-alcoholic steatohepatitis, hepatic encephalopathy, and liver fibrosis). Since is a relatively recent sub-branch genus of the phylum, and since are commonly associated with chronic intestinal inflammation, this narrative review illustrates emerging immunological and mechanistic implications by which spp. correlate with human health.
Topics: Animals; Bacteroidetes; Dysbiosis; Gastrointestinal Microbiome; Host-Pathogen Interactions; Humans; Inflammation; Intestines; Mental Disorders; Mental Health; Neoplasms
PubMed: 32582143
DOI: 10.3389/fimmu.2020.00906 -
Gut Microbes 2021Hypothalamic regulations of food intake are altered during obesity. The dopaminergic mesocorticolimbic system, responsible for the hedonic response to food intake, is... (Review)
Review
Hypothalamic regulations of food intake are altered during obesity. The dopaminergic mesocorticolimbic system, responsible for the hedonic response to food intake, is also affected. Gut microbes are other key players involved in obesity. Therefore, we investigated whether the gut microbiota plays a causal role in hedonic food intake alterations contributing to obesity. We transferred fecal material from lean or diet-induced obese mice into recipient mice and evaluated the hedonic food intake using a food preference test comparing the intake of control and palatable diets (HFHS, High-Fat High-Sucrose) in donor and recipient mice. Obese mice ate 58% less HFHS during the food preference test ( < 0.0001) than the lean donors, suggesting a dysregulation of the hedonic food intake during obesity. Strikingly, the reduction of the pleasure induced by eating during obesity was transferable through gut microbiota transplantation since obese gut microbiota recipient mice exhibited similar reduction in HFHS intake during the food preference test (40% reduction as compared to lean gut microbiota recipient mice, < 0.01). This effect was associated with a consistent trend in modifications of dopaminergic markers expression in the striatum. We also pinpointed a highly positive correlation between HFHS intake and ( < 0.0001), which could represent a potential actor involved in hedonic feeding probably through the gut-to-brain axis. We further demonstrated the key roles played by gut microbes in this paradigm since depletion of gut microbiota using broad-spectrum antibiotics also altered HFHS intake during food preference test in lean mice. In conclusion, we discovered that gut microbes regulate hedonic aspects of food intake. Our data demonstrate that gut microbiota modifications associated with obesity participate in dysregulations of the reward and hedonic components of the food intake. These data provide evidence that gut microbes could be an interesting therapeutic target to tackle hedonic disorders related to obesity.
Topics: Animals; Bacteroidetes; Brain-Gut Axis; Corpus Striatum; Diet, High-Fat; Fecal Microbiota Transplantation; Feeding Behavior; Food Preferences; Gastrointestinal Microbiome; Hyperphagia; Male; Mice; Mice, Inbred C57BL; Obesity; Reward
PubMed: 34424831
DOI: 10.1080/19490976.2021.1959242 -
Mediators of Inflammation 2023We searched PubMed, Cochrane Library, and Epistemonikos to identify systematic reviews and meta-analysis (SRs). We searched for neurological diseases and psychiatric... (Meta-Analysis)
Meta-Analysis Review
METHODS
We searched PubMed, Cochrane Library, and Epistemonikos to identify systematic reviews and meta-analysis (SRs). We searched for neurological diseases and psychiatric disorders, including Alzheimer's disease (AD), attention deficit hyperactivity disorder (ADHD), amyotrophic lateral sclerosis (ALS), autism spectrum disorder (ASD), anorexia nervosa (AN), bipolar disorder (BD), eating disorder (ED), generalized anxiety disorder (GAD), major depressive disorder (MDD), multiple sclerosis (MS), obsessive compulsive disorder (OCD), Parkinson's disease (PD), posttraumatic stress disorder (PTSD), spinal cord injury (SCI), schizophrenia, and stroke. We used A Measurement Tool to Assess Systematic Reviews (AMSTAR-2) to evaluate the quality of included SRs. We also created an evidence map showing the role of gut microbiota in neurological diseases and the certainty of the evidence.
RESULTS
In total, 42 studies were included in this evidence mapping. Most findings were obtained from observational studies. According to the AMSTAR-2 assessment, 21 SRs scored "critically low" in terms of methodological quality, 16 SR scored "low," and 5 SR scored "moderate." A total of 15 diseases have been investigated for the potential association between gut microbiome alpha diversity and disease, with the Shannon index and Simpson index being the most widely studied. A total of 12 diseases were investigated for potential link between beta diversity and disease. At the phylum level, , , , , and were more researched. At the genus level, , , , , , , , , , , , , , and were more researched. Some diseases have been found to have specific flora changes, and some diseases have been found to have common intestinal microbiological changes.
CONCLUSION
We found varied levels of evidence for the associations between gut microbiota and neurological diseases; some gut microbiota increased the risk of neurological diseases, whereas others showed evidence of benefit that gut microbiota might be promising therapeutic targets for such diseases.
Topics: Humans; Gastrointestinal Microbiome; Depressive Disorder, Major; Autism Spectrum Disorder; Bacteria; Firmicutes; Bacteroidetes; Clostridiales
PubMed: 36816743
DOI: 10.1155/2023/5127157 -
Frontiers in Cellular and Infection... 2023The real causal relationship between human gut microbiota and T1D remains unclear and difficult to establish. Herein, we adopted a two-sample bidirectional mendelian...
OBJECTIVE
The real causal relationship between human gut microbiota and T1D remains unclear and difficult to establish. Herein, we adopted a two-sample bidirectional mendelian randomization (MR) study to evaluate the causality between gut microbiota and T1D.
METHODS
We leveraged publicly available genome-wide association study (GWAS) summary data to perform MR analysis. The gut microbiota-related GWAS data from 18,340 individuals from the international consortium MiBioGen were used. The summary statistic data for T1D (n = 264,137) were obtained from the latest release from the FinnGen consortium as the outcome of interest. The selection of instrumental variables conformed strictly to a series of preset inclusion and exclusion criteria. MR-Egger, weighted median, inverse variance weighted (IVW), and weighted mode methods were used to assess the causal association. The Cochran's Q test, MR-Egger intercept test, and leave-one-out analysis were conducted to identify heterogeneity and pleiotropy.
RESULTS
At the phylum level, only Bacteroidetes was indicated to have causality on T1D (OR = 1.24, 95% CI = 1.01-1.53, = 0.044) in the IVW analysis. When it comes to their subcategories, Bacteroidia class (OR = 1.28, 95% CI = 1.06-1.53, = 0.009, = 0.085), Bacteroidales order (OR = 1.28, 95% CI = 1.06-1.53, = 0.009, = 0.085), and group genus (OR = 0.64, 95% CI = 0.50-0.81, = 2.84×10, = 0.031) were observed to have a causal relationship with T1D in the IVW analysis. No heterogeneity and pleiotropy were detected.
CONCLUSIONS
The present study reports that Bacteroidetes phylum, Bacteroidia class, and Bacteroidales order causally increase T1D risk, whereas group genus, which belongs to the Firmicutes phylum, causally decreases T1D risk. Nevertheless, future studies are warranted to dissect the underlying mechanisms of specific bacterial taxa's role in the pathophysiology of T1D.
Topics: Humans; Gastrointestinal Microbiome; Diabetes Mellitus, Type 1; Genome-Wide Association Study; Mendelian Randomization Analysis; Bacteroidetes
PubMed: 37313342
DOI: 10.3389/fcimb.2023.1163898 -
Gut Microbes 2021is the type strain for the genus , a group of gram-negative anaerobic bacteria that commonly colonize the gastrointestinal tract of numerous species. First isolated in... (Review)
Review
is the type strain for the genus , a group of gram-negative anaerobic bacteria that commonly colonize the gastrointestinal tract of numerous species. First isolated in the 1930s from a clinical specimen as , the strain was re-classified to form the new genus in 2006. Currently, the genus consists of 15 species, 10 of which are listed as 'validly named' (, and ) and 5 'not validly named' (, and ) by the List of Prokaryotic names with Standing in Nomenclature. The genus has been associated with reports of both beneficial and pathogenic effects in human health. Herein, we review the literature on the history, ecology, diseases, antimicrobial resistance, and genetics of this bacterium, illustrating the effects of on human and animal health.
Topics: Animals; Anti-Bacterial Agents; Bacteroidetes; Drug Resistance, Bacterial; Gastrointestinal Microbiome; Gram-Negative Bacterial Infections; Humans; Phylogeny; Probiotics
PubMed: 34196581
DOI: 10.1080/19490976.2021.1922241 -
Science (New York, N.Y.) Aug 2022The microbiome contributes to the development and maturation of the immune system. In response to commensal bacteria, intestinal CD4 T lymphocytes differentiate into...
The microbiome contributes to the development and maturation of the immune system. In response to commensal bacteria, intestinal CD4 T lymphocytes differentiate into functional subtypes with regulatory or effector functions. The development of small intestine intraepithelial lymphocytes that coexpress CD4 and CD8αα homodimers (CD4IELs) depends on the microbiota. However, the identity of the microbial antigens recognized by CD4 T cells that can differentiate into CD4IELs remains unknown. We identified β-hexosaminidase, a conserved enzyme across commensals of the Bacteroidetes phylum, as a driver of CD4IEL differentiation. In a mouse model of colitis, β-hexosaminidase-specific lymphocytes protected against intestinal inflammation. Thus, T cells of a single specificity can recognize a variety of abundant commensals and elicit a regulatory immune response at the intestinal mucosa.
Topics: Animals; Bacteroidetes; CD4-Positive T-Lymphocytes; CD8 Antigens; Colitis; Disease Models, Animal; Intestinal Mucosa; Mice; Mice, Inbred C57BL; beta-N-Acetylhexosaminidases
PubMed: 35926021
DOI: 10.1126/science.abg5645 -
Gut Aug 2020Recent evidence points to the gut microbiome's involvement in postoperative outcomes, including after gastrectomy. Here, we investigated the influence of gastrectomy for...
OBJECTIVE
Recent evidence points to the gut microbiome's involvement in postoperative outcomes, including after gastrectomy. Here, we investigated the influence of gastrectomy for gastric cancer on the gut microbiome and metabolome, and how it related to postgastrectomy conditions.
DESIGN
We performed shotgun metagenomics sequencing and capillary electrophoresis time-of-flight mass spectrometry-based metabolomics analyses on faecal samples collected from participants with a history of gastrectomy for gastric cancer (n=50) and compared them with control participants (n=56).
RESULTS
The gut microbiota in the gastrectomy group showed higher species diversity and richness (p<0.05), together with greater abundance of aerobes, facultative anaerobes and oral microbes. Moreover, bile acids such as genotoxic deoxycholic acid and branched-chain amino acids were differentially abundant between the two groups (linear discriminant analysis (LDA) effect size (LEfSe): p<0.05, q<0.1, LDA>2.0), as were also Kyoto Encyclopedia of Genes and Genomes modules involved in nutrient transport and organic compounds biosynthesis (LEfSe: p<0.05, q<0.1, LDA>2.0).
CONCLUSION
Our results reveal alterations of gut microbiota after gastrectomy, suggesting its association with postoperative comorbidities. The multi-omic approach applied in this study could complement the follow-up of patients after gastrectomy.
Topics: Actinobacteria; Aged; Amino Acids, Branched-Chain; Bacillus; Bacteroidetes; Bifidobacterium; Bile Acids and Salts; Case-Control Studies; Clostridiales; Deoxycholic Acid; Feces; Female; Firmicutes; Gastrectomy; Gastrointestinal Microbiome; Humans; Lactobacillus; Male; Metabolome; Metagenomics; Middle Aged; Prevotella; Sequence Analysis, DNA; Stomach Neoplasms; Streptococcus; Veillonella
PubMed: 31953253
DOI: 10.1136/gutjnl-2019-319188 -
Cell Feb 2022The human gut microbiota resides within a diverse chemical environment challenging our ability to understand the forces shaping this ecosystem. Here, we reveal that...
The human gut microbiota resides within a diverse chemical environment challenging our ability to understand the forces shaping this ecosystem. Here, we reveal that fitness of the Bacteroidales, the dominant order of bacteria in the human gut, is an emergent property of glycans and one specific metabolite, butyrate. Distinct sugars serve as strain-variable fitness switches activating context-dependent inhibitory functions of butyrate. Differential fitness effects of butyrate within the Bacteroides are mediated by species-level variation in Acyl-CoA thioesterase activity and nucleotide polymorphisms regulating an Acyl-CoA transferase. Using in vivo multi-omic profiles, we demonstrate Bacteroides fitness in the human gut is associated together, but not independently, with Acyl-CoA transferase expression and butyrate. Our data reveal that each strain of the Bacteroides exists within a unique fitness landscape based on the interaction of chemical components unpredictable by the effect of each part alone mediated by flexibility in the core genome.
Topics: Acyl Coenzyme A; Amino Acid Sequence; Amino Acids, Branched-Chain; Bacteroidetes; Butyrates; Coenzyme A-Transferases; Gastrointestinal Microbiome; Genetic Variation; Hydrogen-Ion Concentration; Metabolome; Polymorphism, Single Nucleotide; Polysaccharides; Promoter Regions, Genetic; Species Specificity; Stress, Physiological; Transcription, Genetic
PubMed: 35120663
DOI: 10.1016/j.cell.2022.01.002 -
Gastroenterology Sep 2020Alterations in the intestinal microbiota affect development of colorectal cancer and drug metabolism. We studied whether the intestinal microbiota affect the ability of...
BACKGROUND & AIMS
Alterations in the intestinal microbiota affect development of colorectal cancer and drug metabolism. We studied whether the intestinal microbiota affect the ability of aspirin to reduce colon tumor development in mice.
METHODS
We performed studies with APC mice and mice given azoxymethane and dextran sulfate sodium to induce colorectal carcinogenesis. Some mice were given antibiotics to deplete intestinal microbes, with or without aspirin, throughout the entire experiment. Germ-free mice were studied in validation experiments. Colon tissues were collected and analyzed by histopathology, quantitative reverse-transcription polymerase chain reaction, and immunoblots. Blood samples and gut luminal contents were analyzed by liquid chromatography/mass spectrometry and an arylesterase activity assay. Fecal samples were analyzed by 16S ribosomal RNA gene and shotgun metagenome sequencing.
RESULTS
Administration of aspirin to mice reduced colorectal tumor number and load in APC mice and mice given azoxymethane and dextran sulfate sodium that had been given antibiotics (depleted gut microbiota), but not in mice with intact microbiota. Germ-free mice given aspirin developed fewer colorectal tumors than conventionalized germ-free mice given aspirin. Plasma levels of aspirin were higher in mice given antibiotics than in mice with intact gut microbiota. Analyses of luminal contents revealed that aerobic gut microbes, including Lysinibacillus sphaericus, degrade aspirin. Germ-free mice fed L sphaericus had lower plasma levels of aspirin than germ-free mice that were not fed this bacterium. There was an inverse correlation between aspirin dose and colorectal tumor development in conventional mice, but this correlation was lost with increased abundance of L sphaericus. Fecal samples from mice fed aspirin were enriched in Bifidobacterium and Lactobacillus genera, which are considered beneficial, and had reductions in Alistipes finegoldii and Bacteroides fragili, which are considered pathogenic.
CONCLUSIONS
Aspirin reduces development of colorectal tumors in APC mice and mice given azoxymethane and dextran sulfate sodium, depending on the presence of intestinal microbes. L sphaericus in the gut degrades aspirin and reduced its chemopreventive effects in mice. Fecal samples from mice fed aspirin were enriched in beneficial bacteria, with reductions in pathogenic bacteria.
Topics: Adenomatous Polyposis Coli Protein; Animals; Anti-Bacterial Agents; Anticarcinogenic Agents; Aspirin; Azoxymethane; Bacillaceae; Bacteroides fragilis; Bacteroidetes; Biological Availability; Carcinogenesis; Colitis; Colon; Colorectal Neoplasms; DNA, Bacterial; Dextran Sulfate; Disease Models, Animal; Dose-Response Relationship, Drug; Feces; Gastrointestinal Microbiome; Germ-Free Life; Humans; Intestinal Mucosa; Male; Mice; Mice, Transgenic; RNA, Ribosomal, 16S
PubMed: 32387495
DOI: 10.1053/j.gastro.2020.05.004