Project description:With increasing age microglia shift toward a pro-inflammatory phenotype and become hyperresponsive to inflammatory stimuli, disrupting brain homeostasis. Soluble fibers have been suggested as a dietary strategy to prevent or reverse microglia dysregulation, due to the bioactive nature of the short chain fatty acids (SCFA; e.g., butyrate) produced during its fermentation in the colon.
Project description:This SuperSeries is composed of the following subset Series:; GSE8146: Age-related transcriptional changes and the effect of dietary supplementation of vitamin E in the mouse heart; GSE8150: Age-related transcriptional changes and the effect of dietary supplementation of vitamin E in the mouse brain Experiment Overall Design: Refer to individual Series
Project description:To understand how dietary fiber affects microglial transcriptome at early stage, we fed mice diets releasing different amount of fiber and profiled microglia at 3 weeks. We found that fiber significantly altered the transcriptomic signature of microglia.
Project description:The investigators hypothesize that an increase in dietary fiber intake during radiation therapy may provide better long-term intestinal health for the cancer survivor. If the hypothesis is not correct, the increased intake may only mean an increase in acute side effects. All participants are advised to consume at least 16 g of dietary fiber/day via food. In addition, participants are invited to take capsules that together contain either 5.5 g of dietary fiber from psyllium husk or placebo.
Project description:This clinical trial tests whether daily fiber supplementation will change the mucosal microbiome of the colon. The microbiome are microorganisms that live in the human gut. They serve a vital role in maintaining health. Certain microbial strains are associated with the growth of colon polyps, which eventually could go on to form colon cancer. Giving dietary fiber supplements may help prevent precancerous polyps from ever developing.
Project description:We sought to examine whether directly dietary fiber application to offspring could also reverse the behavioral and neurobiological deficits characteristic of MHFD offspring. RNA-sequencing (RNA-seq) on mice hippocampus were performed in order to identify the key biological processes and pathways regulated by dietary fiber.
Project description:We established the transcriptional profile of brain aging and examine the global effects of vitamin E supplementation on age-related alterations in expression in the aged mouse brain. Keywords: expression profiling
Project description:Despite accepted health benefits of dietary fiber, little is known about the mechanisms by which fiber deprivation impacts the gut microbiota and alters disease risk. Using a gnotobiotic model, in which mice were colonized with a synthetic human gut microbiota, we elucidated the functional interactions between dietary fiber, the gut microbiota and the colonic mucus barrier, which serves as a primary defence against pathogens. We show that during chronic or intermittent dietary fiber deficiency, the gut microbiota resorts to host-secreted mucus glycoproteins as a nutrient source, leading to erosion of the colonic mucus barrier. Dietary fiber deprivation promoted greater epithelial access and lethal colitis by the mucosal pathogen, Citrobacter rodentium, but only in the presence of a fiber-deprived microbiota that is pushed to degrade the mucus layer. Our work reveals intricate pathways linking diet, gut microbiome and intestinal barrier dysfunction, which could be exploited to improve health using dietary therapeutics. Germ-free mice (Swiss Webster) were colonized with synthetic human gut microbiota comprising of 14 species belonging to five different phyla (names of bacterial species: Bacteroides thetaiotaomicron, Bacteroides ovatus, Bacteroides caccae, Bacteroides uniformis, Barnesiella intestinihominis, Eubacterium rectale, Marvinbryantia formatexigens, Collinsella aerofaciens, Escherichia coli HS, Clostridium symbiosum, Desulfovibrio piger, Akkermansia muciniphila, Faecalibacterium prausnitzii and Roseburia intestinalis). These mice were fed either a fiber-rich diet or a fiber-free diet for about 6 weeks. The mice were then sacrificed and their cecal tissues were immediately flash frozen for RNA extraction. The extracted RNA was subjected to microarray analysis based on Mouse Gene ST 2.1 strips using the Affy Plus kit. Expression values for each gene were calculated using robust multi-array average (RMA) method.
Project description:Cancer cachexia and the associated skeletal muscle wasting are considered poor prognostic factors, although effective treatment has not yet been established. Recent studies have indicated that the pathogenesis of skeletal muscle loss may involve dysbiosis of the gut microbiota and the accompanying chronic inflammation or altered metabolism. In this study, we evaluated the possible effects of modifying the gut microenvironment with partially hydrolyzed guar gum (PHGG), a soluble dietary fiber, on cancer-related muscle wasting and its mechanism using a colon-26 murine cachexia model. Compared to a fiber-free (FF) diet, PHGG contained fiber-rich (FR) diet attenuated skeletal muscle loss in cachectic mice by suppressing the elevation of the major muscle-specific ubiquitin ligases Atrogin-1 and MuRF1, as well as the autophagy markers LC3 and Bnip3. Although tight junction markers were partially reduced in both FR and FF diet-fed cachectic mice, the abundance of Bifidobacterium, Akkermansia, and unclassified S24-7 family increased by FR diet, contributing to the retention of the colonic mucus layer. The reinforcement of the gut barrier function resulted in the controlled entry of pathogens into the host system and reduced circulating levels of lipopolysaccharide-binding protein (LBP) and IL-6, which in turn led to the suppression of proteolysis by downregulating the ubiquitin-proteasome system and autophagy pathway. These results suggest that dietary fiber may have the potential to alleviate skeletal muscle loss in cancer cachexia, providing new insights for developing effective strategies in the future.