Project description:Purpose: Using a C57BL6/J mouse model of diet-induced obesity, we observed that mannose supplementation of high fat diet-fed mice prevents weight gain, lowers adiposity, reduces liver steatosis, and improves glucose tolerance and insulin sensitivity. Mannose increases Bacteroidetes to Firmicutes ratio of the gut microbiota, a signature previously associated with the lean phenotype. These beneficial effects of mannose are observed when supplementation is started early (3 weeks post weaning) but are lost when started later in life (8 weeks post weaning). We profiled transcriptomes of gut microbiota from high fat diet mice supplemented with or without mannose to understand the functional differences of supplementation at 3 weeks post weaning and 8 weeks post weaning. Method: Mice were weaned on high fat diet (HFD) or high fat diet with 2% mannose in drinking water (HFDM). RNA from each mouse for each diet group was isolated individually using Ambion RiboPure Bacteria kit (ThermoFisher Scientific). 1 mg cecal RNA each from 8 mice/diet group was pooled to generate 1 pool/diet for library preparation. The quality of total RNA was assessed by the Agilent Bioanalyzer Nano chip (Agilent Technologies). Total RNA was Ribo-depleted using Ribo-Zero Gold rRNA kit (Epidemiology) (Illumina). RNA-Seq library was constructed from the recovered non-ribosomal RNAs using Truseq Stranded total RNA library preparation kit (Illumina) as per the instructions. Multiplexed libraries were pooled and single-end 50-bp sequencing was performed using an Illumina Hiseq 1500. Results: The comparison of transcriptome profiles of mice supplemented with mannose at 3 weeks post weaning and 8 weeks post weaning shows mannose reduced transcript abundance for glycosyl hydrolases and carbohydrate metabolism when supplied at 3 weeks post weaning. Conclusion: The beneficial effects of mannose in responsive mice (3 weeks post weaning) are at least in part due to reduced energy harvest by gut microbes.
Project description:Long-term dietary intake influences the structure and activity of the trillions of microorganisms residing in the human gut, but it remains unclear how rapidly and reproducibly the human gut microbiome responds to short-term macronutrient change. Here we show that the short-term consumption of diets composed entirely of animal or plant products alters microbial community structure and overwhelms inter-individual differences in microbial gene expression. The animal-based diet increased the abundance of bile-tolerant microorganisms (Alistipes, Bilophila and Bacteroides) and decreased the levels of Firmicutes that metabolize dietary plant polysaccharides (Roseburia, Eubacterium rectale and Ruminococcus bromii). Microbial activity mirrored differences between herbivorous and carnivorous mammals, reflecting trade-offs between carbohydrate and protein fermentation. Foodborne microbes from both diets transiently colonized the gut, including bacteria, fungi and even viruses. Finally, increases in the abundance and activity of Bilophila wadsworthia on the animal-based diet support a link between dietary fat, bile acids and the outgrowth of microorganisms capable of triggering inflammatory bowel disease. In concert, these results demonstrate that the gut microbiome can rapidly respond to altered diet, potentially facilitating the diversity of human dietary lifestyles. RNA-Seq analysis of the human gut microbiome during consumption of a plant- or animal-based diet.
Project description:Gut microbiota has profound effects on obesity and associated metabolic disorders. Targeting and shaping the gut microbiota via dietary intervention using probiotics, prebiotics and synbiotics can be effective in obesity management. Despite the well-known association between gut microbiota and obesity, the microbial alternations by synbiotics intervention, especially at the functional level, are still not characterized. In this study, we investigated the effects of synbiotics on high fat diet (HFD)-induced metabolic disorders, and systematically profiled the microbial profile at both the phylogenetic and functional levels. Synbiotics significantly reversed the HFD-induced change of microbial populations at the levels of richness, taxa and OTUs. Potentially important species Faecalibaculum rodentium and Alistipes putredinis that might mediate the beneficial effects of synbiotics were identified. At the functional level, short chain fatty acid and bile acid profiles revealed that interventions significantly restored cecal levels of acetate, propionate, and butyrate, and synbiotics reduced the elevated total bile acid level. Metaproteomics revealed the effect of synbiotics might be mediated through pathways involved in carbohydrate, amino acid, and energy metabolisms, replication and repair, etc. These results suggested that dietary intervention using our novel synbiotics alleviated HFD-induced weight gain and restored microbial ecosystem homeostasis phylogenetically and functionally.
Project description:Long-term dietary intake influences the structure and activity of the trillions of microorganisms residing in the human gut, but it remains unclear how rapidly and reproducibly the human gut microbiome responds to short-term macronutrient change. Here we show that the short-term consumption of diets composed entirely of animal or plant products alters microbial community structure and overwhelms inter-individual differences in microbial gene expression. The animal-based diet increased the abundance of bile-tolerant microorganisms (Alistipes, Bilophila and Bacteroides) and decreased the levels of Firmicutes that metabolize dietary plant polysaccharides (Roseburia, Eubacterium rectale and Ruminococcus bromii). Microbial activity mirrored differences between herbivorous and carnivorous mammals, reflecting trade-offs between carbohydrate and protein fermentation. Foodborne microbes from both diets transiently colonized the gut, including bacteria, fungi and even viruses. Finally, increases in the abundance and activity of Bilophila wadsworthia on the animal-based diet support a link between dietary fat, bile acids and the outgrowth of microorganisms capable of triggering inflammatory bowel disease. In concert, these results demonstrate that the gut microbiome can rapidly respond to altered diet, potentially facilitating the diversity of human dietary lifestyles.
Project description:The gut microbiome is associated with diverse diseases, but the universal signature of an (un)healthy microbiome remains elusive and there is a need to understand how genetics, exposome, lifestyle and diet shape the microbiome in health and disease. To fill this gap, we profiled bacterial composition, function, antibiotic resistance and virulence factors in the gut microbiomes of 8,208 Dutch individuals from a three-generational cohort comprising 2,756 families. We then correlated this to 241 host and environmental factors, including physical and mental health, medication use, diet, socioeconomic factors and childhood and current exposome.
Project description:<p>We investigate the hypothesis that consistent changes in the human gut microbiome are associated with Crohn's disease, a form of inflammatory bowel disease, and that altered microbiota contributes to pathogenesis. Analysis of this problem is greatly complicated by the fact that multiple factors influence the composition of the gut microbiota, including diet, host genotype, and disease state. For example, data from us and others document a drastic impact of diet on the composition of the gut microbiome. No amount of sequencing will yield a useful picture of the role of the microbiota in disease if samples are confounded with uncontrolled variables.</p> <p>We aim to characterize the composition of the gut microbiome while controlling for diet, host genotype, and disease state. Diet is controlled by analyzing children treated for Crohn's disease by placing them on a standardized elemental diet, and by testing effects of different diets on the gut microbiome composition in adult volunteers. Genotype is analyzed by large scale SNP genotyping, which is already underway and separately funded--team member Hakon Hakonarson is currently genotyping 50 children a week at ~half a million loci each and investigating connections with inflammatory bowel disease. Clinical status is ascertained in the very large IBD practice in the UPenn/CHOP hospital system. Effects of diet, host genotype, and disease state on the gut microbiome are summarized in a multivariate model, allowing connections between microbiome and disease to be assessed free of confounding factors.</p> <p>This project is divided into four sub-studies. In the Fecal Storage Methods (FSM) study, methods of stool storage and DNA extraction are compared to examine their impact on DNA sequence analysis results. The Controlled Feeding Experiment (CaFE) addresses the effects of controlled diets on the gut microbiome. In the Cross-sectional Study of Diet and Stool Microbiome Composition (COMBO), the effects of diet analyzed using surveys and deep sequencing of stool specimens. The fourth study, Pediatric Longitudinal Study of Elemental Diet and Stool Microbiome Composition (PLEASE), examines the effects of an elemental diet treatment on pediatric patients diagnosed with inflammatory bowel disease (IBD), particularly Crohn's disease.</p> <p> <ul> <li>Fecal Storage Methods (FSM): Cross-sectional study</li> <li>Controlled Feeding Experiment (CaFE): Controlled trial</li> <li>Cross-sectional Study of Diet and Stool Microbiome Composition (COMBO): Cross-sectional study</li> <li>Pediatric Longitudinal Study of Elemental Diet and Stool Microbiome Composition (PLEASE): Longitudinal cohort study</li> </ul> </p>
Project description:Background: More than 100 million Americans are living with metabolic syndrome, increasing their propensity to develop heart disease– the leading cause of death worldwide. A major contributing factor to this epidemic is caloric excess, often a result of consuming low cost, high calorie fast food. Several recent seminal studies have demonstrated the pivotal role of gut microbes contributing to cardiovascular disease in a diet-dependent manner. Given the central contributions of diet and gut microbiota to cardiometabolic disease, we hypothesized that novel microbial metabolites originating postprandially after fast food consumption may contribute to cardiometabolic disease progression. Methods: To test this hypothesis, we gave conventionally raised or antibiotic-treated mice a single oral gavage of a fast food slurry or a control rodent chow diet slurry and sacrificed the mice four hours later. Here, we coupled untargeted metabolomics in portal and peripheral blood, 16S rRNA gene sequencing, targeted liver metabolomics, and host liver RNA sequencing to identify novel fast food-derived microbial metabolites. Results: We successfully identified several metabolites that were enriched in portal blood, increased by fast food feeding, and essentially absent in antibiotic-treated mice. Strikingly, just four hours post-gavage, we found that fast food consumption resulted in rapid reorganization of the gut microbial community structure and drastically altered hepatic gene expression. Importantly, diet-driven reshaping of the microbiome and liver transcriptome was dependent on a non-antibiotic ablated gut microbial community. Conclusions: Collectively, these data suggest that single fast food meal is sufficient to reshape the gut microbial community yielding a unique signature of food-derived microbial metabolites. Future studies are warranted to determine if these metabolites are causally linked to cardiometabolic disease.
Project description:The investigators hypothesize that gut microbiome composition and the four bacterial gene markers (M3) show dynamic changes after endoscopic resection of advanced neoplasia, some key bacteria are associated with restoration of gut microbiome after endoscopic resection.