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Biomedicines Nov 2022The role of gut microbes has been suggested in type 2 diabetes (T2DM) risk. However, their results remain controversial. We hypothesized that Asians with T2DM had...
The role of gut microbes has been suggested in type 2 diabetes (T2DM) risk. However, their results remain controversial. We hypothesized that Asians with T2DM had different fecal bacterial compositions, co-abundance networks, and metagenome functions compared to healthy individuals, according to enterotypes. This hypothesis was examined using the combined gut microbiota data from human fecal samples from previous studies. The human fecal bacterial FASTA/Q files from 36 different T2DM studies in Asians were combined (healthy, n = 3378; T2DM, n = 551), and operational taxonomic units (OTUs) and their counts were obtained using qiime2 tools. In the machine learning approaches, fecal bacteria rich in T2DM were found. They were separated into two enterotypes, Lachnospiraceae (ET-L) and Prevotellaceae (ET-P). The Shannon and Chao1 indices, representing α-diversity, were significantly lower in the T2DM group compared to the healthy group in ET-L (p < 0.05) but not in ET-P. In the Shapley additive explanations analysis of ET-L, Escherichia fergusonii, Collinsella aerofaciens, Streptococcus vestibularis, and Bifidobacterium longum were higher (p < 0.001), while Phocaeicola vulgatus, Bacteroides uniformis, and Faecalibacterium prausnitzii were lower in the T2DM group than in the healthy group (p < 0.00005). In ET-P, Escherichia fergusonii, Megasphaera elsdenii, and Oscillibacter valericigenes were higher, and Bacteroides koreensis and Faecalibacterium prausnitzii were lower in the T2DM group than in the healthy group. In ET-L and ET-P, bacteria in the healthy and T2DM groups positively interacted with each other within each group (p < 0.0001) but negatively interacted between the T2DM and healthy groups in the network analysis (p < 0.0001). In the metagenome functions of the fecal bacteria, the gluconeogenesis, glycolysis, and amino acid metabolism pathways were higher, whereas insulin signaling and adenosine 5′ monophosphate-activated protein kinase (AMPK) signaling pathways were lower in the T2DM group than in the healthy group for both enterotypes (p < 0.00005). In conclusion, Asians with T2DM exhibited gut dysbiosis, potentially linked to intestinal permeability and the enteric vagus nervous system.
PubMed: 36428566
DOI: 10.3390/biomedicines10112998 -
Cancer Research Communications Jan 2023Although short-term feeding studies demonstrated effects of grains, fiber, and gluten on gut microbiome composition, the impact of habitual intake of these dietary...
UNLABELLED
Although short-term feeding studies demonstrated effects of grains, fiber, and gluten on gut microbiome composition, the impact of habitual intake of these dietary factors is poorly understood. We examined whether habitual intakes of whole and refined grains, fiber, and gluten are associated with gut microbiota in a cross-sectional study. This study included 779 participants from the multi-ethnic Food and Microbiome Longitudinal Investigation study. Bacterial 16SV4 rRNA gene from baseline stool was amplified and sequenced using Illumina MiSeq. Read clustering and taxonomic assignment was performed using QIIME2. Usual dietary intake was assessed by a 137-item food frequency questionnaire. Association of diet with gut microbiota was assessed with respect to overall composition and specific taxon abundances. Whole grain intake was associated with overall composition, as measured by the Jensen-Shannon divergence (multivariable-adjusted for quartiles = 0.03). The highest intake quartile was associated with higher abundance of , , , and Erysipelotrichaceae and lower abundance of . These bacteria also varied by dietary fiber intake. Higher refined grain and gluten intake was associated with lower Shannon diversity ( < 0.05). These findings suggest that whole grain and dietary fiber are associated with overall gut microbiome structure, largely fiber-fermenting microbiota. Higher refined grain and gluten intakes may be associated with lower microbial diversity.
SIGNIFICANCE
Regular consumption of whole grains and dietary fiber was associated with greater abundance of gut bacteria that may lower risk of colorectal cancer. Further research on the association of refined grains and gluten with gut microbial composition is needed to understand their roles in health and disease.
Topics: Humans; Gastrointestinal Microbiome; Glutens; Cross-Sectional Studies; Diet; Bacteria; Dietary Fiber
PubMed: 36968219
DOI: 10.1158/2767-9764.CRC-22-0154 -
Microbiome Dec 2021Men who have sex with men (MSM) have been disproportionately affected by HIV-1 since the beginning of the AIDS pandemic, particularly in the USA and Europe. Compared to...
BACKGROUND
Men who have sex with men (MSM) have been disproportionately affected by HIV-1 since the beginning of the AIDS pandemic, particularly in the USA and Europe. Compared to men who have sex with women (MSW), MSM have a distinct fecal microbiome regardless of HIV-1 infection. However, it is unclear whether the MSM-associated gut microbiome affects the susceptibility and progression of HIV-1 infection. We studied fecal microbiome profiles, short-chain fatty acids, and blood plasma inflammatory cytokines of 109 HIV-1 seroconverters (SC) from the early, 1984-1985 phase of the HIV-1 pandemic in the Multicenter AIDS Cohort Study (MACS) before and after HIV-1 infection compared to 156 HIV-1-negative MACS MSM (negative controls [NC]).
RESULTS
We found that family Succinivibrionaceae, S24-7, Mogibacteriaceae, Coriobacteriaceae, and Erysipelotrichaceae were significantly higher (p<0.05), whereas Odoribacteraceae, Verucomicrobiaceae, Bacteroidaceae, Barnesiellaceae, and Rikenellaceae were significantly lower (p<0.05), in SC before HIV-1 infection compared to NC. At the species level, Prevotella stercorea, Eubacterium biforme, and Collinsella aerofaciens were significantly higher (p<0.05), and Eubacterium dolichum, Desulfovibrio D168, Alistipes onderdonkii, Ruminococcus torques, Bacteroides fragilis, Bacteroides caccae, Alistipes putredinis, Akkermansia muciniphila, Bacteroides uniformis, and Bacteroides ovatus were significantly lower (p<0.05) in SC before HIV-1 infection compared to NC. After HIV-1 infection, family Prevotellaceae and Victivallaceae and species Bacteroides fragilis and Eubacterium cylindroides were significantly higher (p<0.05) in SC who developed AIDS within 5 years compared to the SC who were AIDS free for more than 10 years without antiretroviral therapy (ART). In addition, family Victivallaceae and species Prevotella stercorea, Coprococcus eutactus, and Butyrivibrio crossotus were significantly higher (p<0.05) and Gemmiger formicilis and Blautia obeum were significantly lower (p<0.05) after HIV-1 infection in SC who developed AIDS within 5-10 years compared to the SC who were AIDS-free for more than 10 years without ART. Furthermore, plasma inflammatory cytokine levels of sCD14, sCD163, interleukin 6, and lipopolysaccharide binding protein were significantly higher in SC with p<0.05 before HIV-1 infection compared to NC.
CONCLUSIONS
Our results suggest that pathogenic changes in the gut microbiome were present in MSM several months prior to infection with HIV-1 in the early phase of the AIDS pandemic in the USA. This was associated with increased inflammatory biomarkers in the blood and risk for development of AIDS. Video abstract.
Topics: Cohort Studies; Female; Gastrointestinal Microbiome; HIV Infections; HIV-1; Homosexuality, Male; Humans; Male; Sexual and Gender Minorities
PubMed: 34879869
DOI: 10.1186/s40168-021-01168-w -
International Journal of Molecular... Oct 2023Non-alcoholic fatty liver disease (NAFLD) is considered the most common chronic liver disease worldwide, affecting nearly 25% of the global adult population. Increasing...
Non-alcoholic fatty liver disease (NAFLD) is considered the most common chronic liver disease worldwide, affecting nearly 25% of the global adult population. Increasing evidence suggests that functional and compositional changes in the gut microbiota may contribute to the development and promote the progression of NAFLD. 16S rRNA gene next-generation sequencing is widely used to determine specific features of the NAFLD microbiome, but a complex system such as the gut microbiota requires a comprehensive approach. We used three different approaches: MALDI-TOF-MS of bacterial cultures, qPCR, and 16S NGS sequencing, as well as a wide variety of statistical methods to assess the differences in gut microbiota composition between NAFLD patients without significant fibrosis and the control group. The listed methods showed enrichment in sp. and for the control samples and enrichment in (and in particular sp.) and in NAFLD. The families, , , and (particularly and ), were also found to be important taxa for NAFLD microbiome evaluation. Considering individual method observations, an increase in and a decrease in for NAFLD patients were detected using MALDI-TOF-MS. An increase in , , , , , and , and a decrease in in NAFLD were observed with 16S NGS, and enrichment in was shown using qPCR analysis. These findings confirm that NAFLD is associated with changes in gut microbiota composition. Further investigations are required to determine the cause-and-effect relationships and the impact of microbiota-derived compounds on the development and progression of NAFLD.
Topics: Adult; Humans; Non-alcoholic Fatty Liver Disease; Gastrointestinal Microbiome; RNA, Ribosomal, 16S; Fibrosis; Microbiota; Bacteroidetes; Liver
PubMed: 37894951
DOI: 10.3390/ijms242015272 -
BMC Microbiology Jan 2021Berberine (BBR) is a plant-based nutraceutical that has been used for millennia to treat diarrheal infections and in contemporary medicine to improve patient lipid...
BACKGROUND
Berberine (BBR) is a plant-based nutraceutical that has been used for millennia to treat diarrheal infections and in contemporary medicine to improve patient lipid profiles. Reduction in lipids, particularly cholesterol, is achieved partly through up-regulation of bile acid synthesis and excretion into the gastrointestinal tract (GI). The efficacy of BBR is also thought to be dependent on structural and functional alterations of the gut microbiome. However, knowledge of the effects of BBR on gut microbiome communities is currently lacking. Distinguishing indirect effects of BBR on bacteria through altered bile acid profiles is particularly important in understanding how dietary nutraceuticals alter the microbiome.
RESULTS
Germfree mice were colonized with a defined minimal gut bacterial consortium capable of functional bile acid metabolism (Bacteroides vulgatus, Bacteroides uniformis, Parabacteroides distasonis, Bilophila wadsworthia, Clostridium hylemonae, Clostridium hiranonis, Blautia producta; B4PC2). Multi-omics (bile acid metabolomics, 16S rDNA sequencing, cecal metatranscriptomics) were performed in order to provide a simple in vivo model from which to identify network-based correlations between bile acids and bacterial transcripts in the presence and absence of dietary BBR. Significant alterations in network topology and connectivity in function were observed, despite similarity in gut microbial alpha diversity (P = 0.30) and beta-diversity (P = 0.123) between control and BBR treatment. BBR increased cecal bile acid concentrations, (P < 0.05), most notably deoxycholic acid (DCA) (P < 0.001). Overall, analysis of transcriptomes and correlation networks indicates both bacterial species-specific responses to BBR, as well as functional commonalities among species, such as up-regulation of Na/H antiporter, cell wall synthesis/repair, carbohydrate metabolism and amino acid metabolism. Bile acid concentrations in the GI tract increased significantly during BBR treatment and developed extensive correlation networks with expressed genes in the B4PC2 community.
CONCLUSIONS
This work has important implications for interpreting the effects of BBR on structure and function of the complex gut microbiome, which may lead to targeted pharmaceutical interventions aimed to achieve the positive physiological effects previously observed with BBR supplementation.
Topics: Animals; Bacteria; Bacterial Proteins; Berberine; Bile Acids and Salts; DNA, Bacterial; DNA, Ribosomal; Female; Gastrointestinal Microbiome; Gene Expression Profiling; Gene Expression Regulation, Bacterial; Male; Metabolomics; Mice; RNA, Ribosomal, 16S; Sequence Analysis, RNA; Species Specificity
PubMed: 33430766
DOI: 10.1186/s12866-020-02020-1 -
Journal of Bacteriology Apr 1990A 65-kilobase-pair element, XBU4422, which has some transposonlike characteristics but carries no known antibiotic resistance genes, has been isolated from Bacteroides... (Comparative Study)
Comparative Study
A 65-kilobase-pair element, XBU4422, which has some transposonlike characteristics but carries no known antibiotic resistance genes, has been isolated from Bacteroides uniformis 0061. XBU4422 was trapped on Bacteroides-Escherichia coli shuttle vectors during experiments in which one of the conjugal Bacteroides tetracycline resistance (Tcr) elements was being used to mobilize the shuttle vectors to Bacteroides recipients. Results of Southern hybridization experiments showed that XBU4422 is normally integrated in the B. uniformis 0061 chromosome and is found only in some strains. Insertion of XBU4422 in the shuttle vectors was site specific and orientation specific. Nonmobilizable vectors that had acquired XBU4422 became transmissible and could be transferred to Bacteroides or E. coli recipients. In B. uniformis transconjugants, the XBU4422 insertion in the vectors was usually intact, but XBU4422 was always lost in matings with E. coli, Bacteroides thetaiotaomicron, or B. ovatus. The loss of XBU4422 did not visibly alter the vector; in the case of E. coli, the loss of the insertion appeared to be RecA dependent. Although XBU4422 carried no antibiotic resistances, it shared regions of homology with six conjugal Bacteroides Tcr elements; this homology was strongest with the ends of XBU4422. Using a strain of B. thetaiotaomicron that contains no XBU4422-hybridizing sequences, we showed that the ends of XBU4422 were probably reacting with the ends of the Tcr elements. These results provide the first direct evidence that the Tcr elements, like XBU4422, are integrated in the chromosome and that insertion of the least some Tcr elements, such as TcrEmr DOT, is relatively site specific.
Topics: Bacteroides; Blotting, Southern; Chromosomes, Bacterial; Conjugation, Genetic; DNA Transposable Elements; DNA, Bacterial; Escherichia coli; Genetic Vectors; Phenotype; Plasmids; R Factors; Restriction Mapping; Sequence Homology, Nucleic Acid; Tetracycline Resistance
PubMed: 2156799
DOI: 10.1128/jb.172.4.1694-1702.1990 -
Frontiers in Microbiology 2023Spaceflight and microgravity has a significant impact on the immune, central nervous, bone, and muscle support and cardiovascular systems. However, limited studies are...
Spaceflight and microgravity has a significant impact on the immune, central nervous, bone, and muscle support and cardiovascular systems. However, limited studies are available on the adverse effects of long-term microgravity on the intestinal microbiota, metabolism, and its relationships. In this study, a ground-based simulated microgravity (SMG) mouse model was established to evaluate the impact of long-term microgravity on gut microbiota and metabolome. After 8 weeks of SMG, alterations of the intestinal microbiota and metabolites were detected using 16S rRNA sequencing and untargeted metabolomics. Compared to the control, no significant differences in α-diversity were observed at weeks 2, 4 and 8. Nevertheless, there were clear differences in community structures at different time points. The phylum significantly declined from 2 to 8 weeks of SMG, yet the relative abundance of and expanded remarkably at weeks 8. SMG decreased the genus of and increased significantly throughout the period of 8 weeks. Besides, Genus , , , , , , , and were identified as biomarkers for SMG group. , and dropped at week 2, which tend to recover at week 4, except for . and declined significantly, while and elevated at week 8. Furthermore, intestinal metabolome analysis showed that 129 were upregulated and 146 metabolites were downregulated in SMG. Long-term SMG most affected steroid hormone biosynthesis, tryptophan, cysteine, methionine, arginine, proline metabolism, and histidine metabolism. Correlated analysis suggested that the potential beneficial taxa , and were negatively associated with tryptophan, histidine, arginine, and proline metabolism, but positively with steroid hormone biosynthesis. Yet and were positively correlated with arginine, proline, tryptophan, and histidine metabolism, while negatively associated with steroid hormone biosynthesis. These results suggest that Long-term SMG altered the community of intestinal microbiota, and then further disturbed intestinal metabolites and metabolic pathways, which have great potential to help understand and provide clues for revealing the mechanisms of long-term SMG involved diseases.
PubMed: 37032862
DOI: 10.3389/fmicb.2023.1100747 -
The Journal of Nutrition Sep 2021Healthy plant-based diet index (hPDI) is associated with a lower risk of cardiometabolic conditions, but its association as well as interactions with microbiome have not...
BACKGROUND
Healthy plant-based diet index (hPDI) is associated with a lower risk of cardiometabolic conditions, but its association as well as interactions with microbiome have not been elucidated.
OBJECTIVES
We aimed to investigate the interrelations between hPDI, gut microbiome, and cardiometabolic risk markers.
METHODS
hPDI was derived from dietary assessments by a validated FFQ and was examined in relation to metagenomic profiles of 911 fecal samples collected from 303 men aged 71 ± 4 y with an average BMI (in kg/m2) of 25.2 ± 3.6 in the Men's Lifestyle Validation Study. Principal coordinate (PCo) analysis based on Bray-Curtis dissimilarity was conducted, and interactions between hPDI and PCo were examined by using a metabolic risk score composed of blood lipids, BMI, and glycated hemoglobin.
RESULTS
After multivariable adjustment, hPDI was significantly associated with the relative abundance of 7 species and 9 pathways. In particular, higher hPDI was significantly associated with a higher relative abundance of Bacteroides cellulosilyticus and Eubacterium eligens, amino acid biosynthesis pathways (l-isoleucine biosynthesis I and III and l-valine biosynthesis), and the pathway of pyruvate fermentation to isobutanol. A favorable association between hPDI and the metabolic risk score was more pronounced among men with a higher PCo characterized by higher abundance of Bacteroides uniformis and lower abundance of Prevotella copri. At the individual species level, a similar interaction was also observed between hPDI and P. copri, as well as with Clostridium clostridioforme or Blautia hydrogenotrophica (all P-interaction < 0.01).
CONCLUSION
A greater adherence to a healthy plant-based diet by older men was associated with a microbial profile characterized by a higher abundance of multiple species, including B. cellulosilyticus and E. eligens, as well as pathways in amino acid metabolism and pyruvate fermentation. In addition, inverse associations between healthy plant-based diet and human metabolic risk may partially depend on microbial compositions.
Topics: Aged; Diet; Diet, Healthy; Diet, Vegetarian; Feces; Gastrointestinal Microbiome; Humans; Male
PubMed: 34114015
DOI: 10.1093/jn/nxab175 -
International Journal of Molecular... May 2023T2DM etiology differs among Asians and Caucasians and may be associated with gut microbiota influenced by different diet patterns. However, the association between fecal...
T2DM etiology differs among Asians and Caucasians and may be associated with gut microbiota influenced by different diet patterns. However, the association between fecal bacterial composition, enterotypes, and T2DM susceptibility remained controversial. We investigated the fecal bacterial composition, co-abundance network, and metagenome function in US adults with T2DM compared to healthy adults based on enterotypes. We analyzed 1911 fecal bacterial files of 1039 T2DM and 872 healthy US adults from the Human Microbiome Projects. Operational taxonomic units were obtained after filtering and cleaning the files using Qiime2 tools. Machine learning and network analysis identified primary bacteria and their interactions influencing T2DM incidence, clustered into enterotypes, Bacteroidaceae (ET-B), Lachnospiraceae (ET-L), and Prevotellaceae (ET-P). ET-B showed higher T2DM incidence. Alpha-diversity was significantly lower in T2DM in ET-L and ET-P ( < 0.0001), but not in ET-B. Beta-diversity revealed a distinct separation between T2DM and healthy groups across all enterotypes ( < 0.0001). The XGBoost model exhibited high accuracy and sensitivity. , , , and were more abundant in the T2DM group than in the healthy group. , , , and were lower in the T2DM than in the healthy group regardless of the enterotypes in the XGBoost model ( < 0.0001). However, the patterns of microbial interactions varied among different enterotypes affecting T2DM risk. The interaction between fecal bacteria was more tightly regulated in the ET-L than in the ET-B and ET-P groups ( < 0.001). Metagenomic analysis revealed an inverse association between bacteria abundance in T2DM, energy utility, butanoate and propanoate metabolism, and the insulin signaling pathway ( < 0.0001). In conclusion, fecal bacteria play a role in T2DM pathogenesis, particularly within different enterotypes, providing valuable insights into the link between gut microbiota and T2DM in the US population.
Topics: Adult; Humans; Metagenome; Diabetes Mellitus, Type 2; Microbiota; Gastrointestinal Microbiome; Feces; Bacteria
PubMed: 37298483
DOI: 10.3390/ijms24119533 -
Journal of Neurogastroenterology and... Sep 2020The pathophysiology of functional abdominal bloating and distention (FABD) is unclear yet. Our aim is to compare the diversity and composition of fecal microbiota in...
BACKGROUND/AIMS
The pathophysiology of functional abdominal bloating and distention (FABD) is unclear yet. Our aim is to compare the diversity and composition of fecal microbiota in patients with FABD and healthy individuals, and to evaluate the relationship between small intestinal bacterial overgrowth (SIBO) and dysbiosis.
METHODS
The microbiota of fecal samples was analyzed from 33 subjects, including 12 healthy controls and 21 patients with FABD diagnosed by the Rome IV criteria. FABD patients underwent a hydrogen breath test. Fecal microbiota composition was determined by 16S ribosomal RNA amplification and sequencing.
RESULTS
Overall fecal microbiota composition of the FABD group differed from that of the control group. Microbial diversity was significantly lower in the FABD group than in the control group. Significantly higher proportion of Proteobacteria and significantly lower proportion of Actinobacteria were observed in FABD patients, compared with healthy controls. Compared with healthy controls, significantly higher proportion of in FABD patients and significantly higher proportion of and in SIBO (+) patients with FABD were found. , was significantly more abundant, but and were significantly less abundant in patients with FABD, compared with healthy controls. Significantly more abundant and , and significantly less abundant and were observed in SIBO (+) patients, compared with healthy controls.
CONCLUSION
The fecal microbiota profiles in FABD patients are different from those in healthy controls, particularly in SIBO (+) patients, suggesting a role of gut microbiota in the pathogenesis of FABD.
PubMed: 32989189
DOI: 10.5056/jnm20080