Project description:Background & Aims: The complex interactions between diet and the microbiota that influence mucosal inflammation and inflammatory bowel disease are poorly understood. Experimental colitis models provide the opportunity to control and systematically perturb diet and the microbiota in parallel to quantify the contributions between multiple dietary ingredients and the microbiota on host physiology and colitis. Methods: To examine the interplay of diet and the gut microbiota on host health and colitis, we fed over 40 different diets with varied macronutrient sources and concentrations to specific pathogen free or germ free mice either in the context of healthy, unchallenged animals or dextran sodium sulfate colitis model. Results: Diet influenced physiology in both health and colitis across all models, with the concentration of protein and psyllium fiber having the most profound effects. Increasing dietary protein elevated gut microbial density and worsened DSS colitis severity. Depleting gut microbial density by using germ-free animals or antibiotics negated the effect of a high protein diet. Psyllium fiber influenced host physiology and attenuated colitis severity through microbiota-dependent and microbiota-independent mechanisms. Combinatorial perturbations to dietary protein and psyllium fiber in parallel explain most variation in gut microbial density, intestinal permeability, and DSS colitis severity, and changes in one ingredient can be offset by changes in the other. Conclusions: Our results demonstrate the importance of examining complex mixtures of nutrients to understand the role of diet in intestinal inflammation. Keywords: IBD; Diet; Microbiota; Mouse Models; Systems Biology
Project description:To explore the changes in the composition and diversity of intestinal microbiota during 3-weeks of modified MAC diet and conventional diet in stage I or low-risk stage II colorectal cancer (CRC) patients after surgery. Additionally, the investigator analyze the association of gut microbiota and stool formation pattern or quality of life according to dietary pattern. Therefore, the investigator identify the beneficial or harmful microbiota composition and diversity adapting modified MAC diet that related to cancer recurrence, which provide supporting evidence for future prospective trial.
Project description:A high-sugar diet induces lifestyle-associated metabolic diseases, such as obesity and diabetes, which may underlie the pro-tumor effects of a high-sugar diet. We supplied GL261 syngeneic glioblastoma (GBM) model mice with a short-term high-glucose diet (HGD) and found an increased survival rate with no evidence of metabolic disease. Modulation of the gut microbiota by an HGD was critical for enhancing the anti-tumor immune response. Single-cell RNA sequencing showed that modulation of the gut microbiota by an HGD increased the T cell-mediated anti-tumor immune response in GBM mice. We found that the cytotoxic CD4+ T cell population in GBM mice increased due to synergy with anti-PD-1 immune checkpoint inhibitors, but this depended on an HGD. Thus, we determined that an HGD enhanced anti-tumor immune responses in GBM mice through changes in the gut microbiota and suggest that the role of an HGD in GBM should be re-examined.
Project description:Abstract: Histones are small proteins that form the core of nucleosomes, around which eukaryotic DNA wraps to ultimately form the highly organized and compressed structure known as chromatin. The N-terminal tails of histones are highly modified, and the modification state of these proteins dictates whether chromatin is permissive or repressive to processes that require physical access to DNA, including transcription and DNA replication and repair. The enzymes that add and remove histone modifications are known to be exquisitely sensitive to endogenous small molecule metabolite availability. In this manner, chromatin can adapt to changes in environment, particularly diet-induced metabolic state. Importantly, gut microbiota contribute to robust host metabolic phenotypes, and produce a myriad of metabolites that are detectable in host circulation. Further, gut microbial community composition and metabolite production are regulated by host diet, as a major source of carbon and energy for the microbiota. While prior studies have reported robust host metabolic associations with gut microbiota, the mechanisms therein remain largely unknown. Here we demonstrate that microbial colonization regulates global histone acetylation and methylation in multiple host tissues including colon, adipose tissue, and liver. This regulatory relationship is altered by diet: a “Western-type” diet leads to a general suppression of the microbiota-dependent chromatin changes observed in a polysaccharide rich diet. Finally, we demonstrate that supplementation of germ-free mice with major products of gut bacterial fermentation (i.e., short-chain fatty acids acetate, propionate, and butyrate) is sufficient to recapitulate many of the effects of colonization on host epigenetic states. These findings have profound implications for understanding the complex functional interactions between diet, gut microbiota, and host health.
Project description:Abstract: Histones are small proteins that form the core of nucleosomes, around which eukaryotic DNA wraps to ultimately form the highly organized and compressed structure known as chromatin. The N-terminal tails of histones are highly modified, and the modification state of these proteins dictates whether chromatin is permissive or repressive to processes that require physical access to DNA, including transcription and DNA replication and repair. The enzymes that add and remove histone modifications are known to be exquisitely sensitive to endogenous small molecule metabolite availability. In this manner, chromatin can adapt to changes in environment, particularly diet-induced metabolic state. Importantly, gut microbiota contribute to robust host metabolic phenotypes, and produce a myriad of metabolites that are detectable in host circulation. Further, gut microbial community composition and metabolite production are regulated by host diet, as a major source of carbon and energy for the microbiota. While prior studies have reported robust host metabolic associations with gut microbiota, the mechanisms therein remain largely unknown. Here we demonstrate that microbial colonization regulates global histone acetylation and methylation in multiple host tissues including colon, adipose tissue, and liver. This regulatory relationship is altered by diet: a “Western-type” diet leads to a general suppression of the microbiota-dependent chromatin changes observed in a polysaccharide rich diet. Finally, we demonstrate that supplementation of germ-free mice with major products of gut bacterial fermentation (i.e., short-chain fatty acids acetate, propionate, and butyrate) is sufficient to recapitulate many of the effects of colonization on host epigenetic states. These findings have profound implications for understanding the complex functional interactions between diet, gut microbiota, and host health.
Project description:To elucidate the underlying mechanisms of pro-inflammatory diet in regulating intestinal inflammation. We performed gene expression profiling analysis using data obtained from RNA-seq of colon tissues from mice treatment with or without pro-inflammatory diet.
Project description:Despite the benefits associated with healthy diets, data on the mechanisms by which these benefits are promoted are scarce. Our aim was to explore the global transcriptomic response of biological pathways related to cardiovascular disease associated with traditional Mediterranean diet (TMD) intervention. The PREDIMED study is a large on-going, parallel, multicentre, randomised, controlled trial aimed at assessing the TMD effect on primary cardiovascular prevention. High cardiovascular risk participants were recruited and assigned to one of the following interventions: 1) TMD plus virgin olive oil (VOO); 2) TMD plus mixed nuts; or 3) low-fat diet (control group). In a sub sample of 30 volunteers of the PREDIMED- Barcelona Sur Centre, gene expression changes in peripheral mononuclear cells, after 3 months of intervention, were assessed by microarray analysis. A parallel study comparing three diet interventions: We analyzed 65 arrays which belonged to 34 patients, 31 microarrays at baseline (11 baseline group 1; 11 baseline group 2; 9 baseline group 3) and 34 microarrays after the 3 month intervention (11 for group 1; 11 for group 2; and 12 for group 3). The three interventions were: Group 1: 3-month Traditional Mediterranean Diet enriched with virgin olive oil; Group 2: 3-month Traditional Mediterranean Diet enriched with nuts; and Group 3: 3-month Low Fat Diet.
Project description:The relationship between retinal disease, diet, and the gut microbiome has shown increasing importance over recent years. In particular, high-fat diets (HFDs) are associated with development and progression of several retinal diseases, including age-related macular degeneration (AMD) and diabetic retinopathy. However, the complex, overlapping interactions between diet, gut microbiome, and retinal homeostasis are poorly understood. Using high-throughput RNA-sequencing (RNA-seq) of whole retinas, we compare the retinal transcriptome from germ-free (GF) mice on a regular diet (ND) and HFD to investigate transcriptomic changes without influence of gut microbiome. After correction of raw data, 53 differentially expressed genes (DEGs) were identified, of which 19 were upregulated and 34 were downregulated in GF-HFD mice. Key genes involved in retinal inflammation, angiogenesis, and RPE function were identified. Enrichment analysis revealed that the top 3 biological processes affected were regulation of blood vessel diameter, inflammatory response, and negative regulation of endopeptidase. Molecular functions altered include endopeptidase inhibitor activity, protease binding, and cysteine-type endopeptidase inhibitor activity. Human and mouse pathway analysis revealed that the complement and coagulation cascades are significantly affected by HFD. This study demonstrates novel data that diet can directly modulate the retinal transcriptome independently of the gut microbiome.
Project description:This data is part of a miRNA platform comparison study. We compared the performance characteristics of four commercial miRNA array technologies and found that all platforms performed well in separate measures of performance. The Ambion and Agilent platforms were more accurate, whereas the Illumina and Exiqon platforms were more specific. Furthermore, the data analysis approach had a large impact on the performance, predominantly by improving precision. Performance of four (4) commercially available miRNA platforms was evaluated using 7 placenta samples spiked with synthetic microRNA spikes (in Latin-square design) absent in placenta. Platforms were primarily evaluated for accuracy and specificity.