Project description:The gut microbiome is a malleable microbial community that can remodel in response to various factors, including diet, and contribute to the development of several chronic diseases, including atherosclerosis. We devised an in vitro screening protocol of the mouse gut microbiome to discover molecules that can selectively modify bacterial growth. This approach was used to identify cyclic D,L-α-peptides that remodeled the Western diet (WD) gut microbiome toward the low-fat-diet microbiome state. Daily oral administration of the peptides in WD-fed LDLr-/- mice reduced plasma total cholesterol levels and atherosclerotic plaques. Depletion of the microbiome with antibiotics abrogated these effects. Peptide treatment reprogrammed the microbiome transcriptome, suppressed the production of pro-inflammatory cytokines (including interleukin-6, tumor necrosis factor-α and interleukin-1β), rebalanced levels of short-chain fatty acids and bile acids, improved gut barrier integrity and increased intestinal T regulatory cells. Directed chemical manipulation provides an additional tool for deciphering the chemical biology of the gut microbiome and might advance microbiome-targeted therapeutics.
Project description:Although critical for studies of gut motility and intestinal regeneration, the in vitro culture of intestinal muscularis with peristaltic function remains a significant challenge. Periodic contractions of intestinal muscularis result from the coordinated activity of smooth muscle cells (SMC), the enteric nervous system (ENS), and interstitial cells of Cajal (ICC). Reproducing this activity requires the preservation of all these cells in one system. Here we report the first serum-free culture methodology that consistently maintains spontaneous and periodic contractions of murine and human intestinal muscularis cells for months. In this system, SMC expressed the mature marker myosin heavy chain, and multipolar/dipolar ICC, uniaxonal/multipolar neurons and glial cells were present. Furthermore, drugs affecting neural signals, ICC or SMC altered the contractions. Combining this method with scaffolds, contracting cell sheets were formed with organized architecture. With the addition of intestinal epithelial cells, this platform enabled up to 11 types of cells from mucosa, muscularis and serosa to coexist and epithelial cells were stretched by the contracting muscularis cells. The method constitutes a powerful tool for mechanistic studies of gut motility disorders and the functional regeneration of the engineered intestine.
Project description:Little is known about how interactions between diet, intestinal stem cells (ISCs) and immune cells impact the early steps of intestinal tumorigenesis. Here, we show that a high fat diet (HFD) reduces the expression of the major histocompatibility complex II (MHC-II) genes in intestinal epithelial cells including ISCs. This decline in epithelial MHC-II expression in a HFD correlates with reduced diversity of the intestinal microbiome and is recapitulated in antibiotic treated and germ-free mice on a control diet. Mechanistically, pattern recognition receptor (PRR) and IFN g signaling regulate epithelial MHC-II expression where genetic ablation of these signaling pathways dampen MHC-II epithelial expression. Interestingly, upon loss of the tumor suppressor gene Apc in a HFD, MHC-II- ISCs harbor greater in vivo tumor-initiating capacity than their MHC-II+ counterparts when transplanted into immune-component hosts but not immune-deficient hosts, thus implicating a role for epithelial MHC-II-mediated immune surveillance in suppressing tumorigenesis. Finally, ISC-specific genetic ablation of MHC-II in engineered Apc-mediated intestinal tumor models increases tumor burden in a cell autonomous manner. These findings highlight how a HFD perturbs a microbiome – stem cell – immune cell crosstalk in the intestine and contributes to tumor initiation through the dampening of MHC-II expression in pre-malignant ISCs.
Project description:Microbiome DNA from the adhering fraction of a sheep rumen. The RSTs were generated using an improved version of SARST (referred to as iSARST) from the microbiome DNA extracted from the adhering fraction of the rumen content taken from a sheep. The iSARST method is going to be submitted to Nature Biotechnology for publication. Keywords: other
Project description:We found that western diet consumption resulted in decrease in the percentage of normal Paneth cell population in wild type mice, indicating that western diet could negatively affect Paneth cell function. Subsequent generations of western diet consumption further reduced percentages of normal Paneth cell population. We performed fecal microbiota composition profiling. Male mice were used at 4-5 weeks of age. Fecal samples were collected for microbiome analysis.
Project description:We found that low protein diet consumption resulted in decrease in the percentage of normal Paneth cell population in wild type mice, indicating that low protein diet could negatively affect Paneth cell function. We performed fecal microbiota composition profiling. Male mice were used at 4-5 weeks of age. Fecal samples were collected for microbiome analysis.
Project description:We reported the variation in the gut microbiome diversity under the influence of Intrauterine Growth restriction or Exposure to High Fat High fructose diet followed by Intrauterine growth restriction.
Project description:Pancreatic cancer is the 3rd most prevalent cause of cancer related deaths in United states alone, with over 55000 patients being diagnosed in 2019 alone and nearly as many succumbing to it. Late detection, lack of effective therapy and poor understanding of pancreatic cancer systemically contributes to its poor survival statistics. Obesity and high caloric intake linked co-morbidities like type 2 diabetes (T2D) have been attributed as being risk factors for a number of cancers including pancreatic cancer. Studies on gut microbiome has shown that lifestyle factors as well as diet has a huge effect on the microbial flora of the gut. Further, modulation of gut microbiome has been seen to contribute to effects of intensive insulin therapy in mice on high fat diet. In another study, abnormal gut microbiota was reported to contribute to development of diabetes in Db/Db mice. Recent studies indicate that microbiome and microbial dysbiosis plays a role in not only the onset of disease but also in its outcome. In colorectal cancer, Fusobacterium has been reported to promote therapy resistance. Certain intra-tumoral bacteria have also been shown to elicit chemo-resistance by metabolizing anti-cancerous agents. In pancreatic cancer, studies on altered gut microbiome have been relatively recent. Microbial dysbiosis has been observed to be associated with pancreatic tumor progression. Modulation of microbiome has been shown to affect response to anti-PD1 therapy in this disease as well. However, most of the studies in pancreatic cancer and microbiome have remained focused om immune modulation. In the current study, we observed that in a T2D mouse model, the microbiome changed significantly as the hyperglycemia developed in these animals. Our results further showed that, tumors implanted in the T2D mice responded poorly to Gemcitabine/Paclitaxel (Gem/Pac) standard of care compared to those in the control group. A metabolomic reconstruction of the WGS of the gut microbiota further revealed that an enrichment of bacterial population involved in drug metabolism in the T2D group.
Project description:The long-term study objective is to develop optimized nutritional therapies for surgery and test them in clinical practice. This pilot study will test a microbiome-optimization diet in colorectal cancer surgery patients. The study hypothesizes that the Bacterial Intestinal Gut Modification Around Cancer Surgery (BIG MACS) Diet will provide participants with increased microbiota accessible carbohydrates (MACs) to support the microbiome and improve outcomes.