Project description:We have previously demonstrated that the gut microbiota can play a role in the pathogenesis of conditions associated with exposure to environmental pollutants. It is well accepted that diets high in fermentable fibers such as inulin can beneficially modulate the gut microbiota and lessen the severity of pro-inflammatory diseases. Therefore, we aimed to test the hypothesis that hyperlipidemic mice fed a diet enriched with inulin would be protected from the pro-inflammatory toxic effects of PCB 126.
Project description:Consumption of diets rich in fibers has been associated with several beneficial effects on gastrointestinal health. However, detailed studies on the molecular effects of fibers in colon are limited. In this study we investigated and compared the influence of five different fibers on the mucosal transcriptome, and luminal microbiota and SCFA concentrations in murine colon. Mice were fed diets enriched with fibers that differed in carbohydrate composition, namely inulin (IN), oligofructose (FOS), arabinoxylan (AX), guar gum (GG), resistant starch (RS) or a control diet (corn starch) for 10 days. Gene expression profiling revealed the regulation of specific, but also overlapping sets of epithelial genes by each fiber, which on a functional level were mainly linked to cell cycle and various metabolic pathways including fatty acid oxidation, tricarboxylic acid cycle, and electron transport chain. In addition, the transcription factor PPAR was predicted to be a prominent upstream regulator of these processes. Microbiota profiles were distinct per dietary fiber, but the fibers IN, FOS, AX and GG induced a common change in microbial groups. All dietary fibers, except resistant starch, increased SCFA concentrations but to a different extent. Multivariate data integration revealed strong correlations between the expression of genes involved in energy metabolism and the relative abundance of bacteria belonging to the group of Clostridium cluster XIVa, that are known butyrate producers. These findings illustrate the potential of multivariate data analysis to unravel simple relationships in complex systems. Keywords: Expression profiling by array Mice received a control diet, or a diet supplemented with 10% dietary fibers for 10 days. After an overnight fast colon was removed, epithelial cells were scraped off, and subjected to gene expression profiling.
Project description:Background: Beneficial microbes can be actors in maintaining or stimulating barrier function, and may counteract pathogen-infection. Lactobacilli are particularly recognized for enhancing intestinal barrier function and to confer protective effects against multiresistant pathogens. Various L. acidophilus strains support intestinal immune barrier function and have been shown to improve resistance to pathogens. Although less extensively studied than beneficial bacteria, other food-based ingredients that can contribute to strengthening barrier function are dietary fibers. For instance, inulin and fructooligosaccharides (FOS) have recently been shown to enhance barrier function and protect against barrier dysfunction. Effects of these ingredients on intestinal barrier function were evaluated by quantifying regulation of gene expression by microarray. Methods: Caco-2 cells were incubated with probiotic strains or inulin-type fibers for 6 hours, total RNA was extracted and Affymterix Human Gene 1.1 ST arrays were used to analyze the gene expression profiles. Results: Only L. acidophilus modulated a group of 26 genes related to tight-junctions. Inulin-type fructans, L. brevis W63 and L. casei W56 regulated other genes, unrelated to tight junctions. L. acidophilus also had unique effects on a group of 6 genes regulating epithelial phenotype towards follicle-associated epithelium. L. acidophilus W37 was therefore selected for a challenge with STM and prevented STM-induced barrier disruption and decreased secretion of IL-8. L. acidophilus W37 increases TEER and can protect against STM induced disruption of gut epithelial cells integrity in vitro. Conclusion: Our results suggest that selection of specific bacterial strains for enforcing barrier function may be a promising strategy to reduce or prevent STM infections.
2018-07-19 | GSE115022 | GEO
Project description:dynamics of microbial community on inulin fermentation
Project description:Milk contains microRNAs (miRNAs) that are protected by extracellular vesicles (EV). Beyond variations among individuals, the nutritional conditions of cattle play a role in shaping these milk miRNA profiles. This study explored milk-derived EV-miRNA variations induced by inulin supplementation and analyzed involved pathways. Fourteen lactating cows with sub-clinical mastitis were equally and randomly divided into an inulin and a control group. Cows in the inulin group received 300 g/d inulin, while the control group did not. After one week of adaptation and five weeks of treatment, milk-derived EV-miRNAs from cows were isolated. Differentially expressed (DE) miRNAs were identified via high-throughput sequencing. Functional enrichment analyses, including Gene Ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses, were conducted to examine the target genes of DE miRNAs. Inulin supplementation did not significantly alter miRNA length, the number of known miRNAs, or the read number of small RNAs.
Project description:Dietary fiber such as inulin have been reported to promote cardiovascular and metabolic health. However, the mechanisms involved are not well understood. We studied effects of inulin on lipid metabolism in Ldlr deficient atherosclerosis mouse model using lipidomics and transcriptomics. Plasma and tissues were collected at 10 days and/or 12 weeks after feeding an atherogenic diet supplemented with inulin or cellulose (control).
Project description:Consumption of diets rich in fibers has been associated with several beneficial effects on gastrointestinal health. However, detailed studies on the molecular effects of fibers in colon are limited. In this study we investigated and compared the influence of five different fibers on the mucosal transcriptome, and luminal microbiota and SCFA concentrations in murine colon. Mice were fed diets enriched with fibers that differed in carbohydrate composition, namely inulin (IN), oligofructose (FOS), arabinoxylan (AX), guar gum (GG), resistant starch (RS) or a control diet (corn starch) for 10 days. Gene expression profiling revealed the regulation of specific, but also overlapping sets of epithelial genes by each fiber, which on a functional level were mainly linked to cell cycle and various metabolic pathways including fatty acid oxidation, tricarboxylic acid cycle, and electron transport chain. In addition, the transcription factor PPAR was predicted to be a prominent upstream regulator of these processes. Microbiota profiles were distinct per dietary fiber, but the fibers IN, FOS, AX and GG induced a common change in microbial groups. All dietary fibers, except resistant starch, increased SCFA concentrations but to a different extent. Multivariate data integration revealed strong correlations between the expression of genes involved in energy metabolism and the relative abundance of bacteria belonging to the group of Clostridium cluster XIVa, that are known butyrate producers. These findings illustrate the potential of multivariate data analysis to unravel simple relationships in complex systems. Keywords: Expression profiling by array
Project description:MicroRNA (miRNA) profiles vary with the nutritional and pathological conditions of cattle. In this study, we aimed to investigate the effects of inulin supplement on miRNA profiles derived from serum extracellular vesicles (EVs). Our goal was to determine the differences in miRNA expressions and analyse the pathways in which they are involved. Based on the results of California mastitis test and milk somatic cell counts, ten lactating cows with subclinical mastitis were randomly divided into two groups: an inulin group and a control group (n = 5 in each group). The inulin group received a daily supplement of 300 g of inulin while the control group did not receive any supplementation. After a 5-week treatment period, serum-derived EV-miRNAs from each cow were isolated. High-throughput sequencing was conducted to identify differentially expressed miRNAs. GO and KEGG bioinformatics analysis was performed to examine the target genes of these differentially expressed miRNAs. The EV-RNA concentration and small RNA content were not affected by the inulin treatment. A total of 162 known miRNAs and 180 novel miRNAs were identified from 10 samples in the two groups. Among the known miRNAs, 23 miRNAs were found to be differentially expressed between the two groups, with 18 upregulated and five downregulated in the inulin group compared to the control group. Pathway analysis revealed the involvement of these differentially expressed miRNAs in the regulation of cell structure and function, lipid oxidation and metabolism, immunity and inflammation, as well as digestion and absorption of nutrients. Overall, our study provides a molecular-level explanation for the reported beneficial health effects of inulin supplementation in cows with subclinical mastitis.
Project description:Human umbilical cord Wharton’s jelly stem cells (WHJSC) are gaining attention as a possible clinical source of mesenchymal stem cells for use in cell therapy and tissue engineering due to their high accessibility, expansion potential and plasticity. However, the cell viability changes that are associated to sequential cell passage of these cells are not known. In this analysis, we have identified the gene expression changes that are associated to cell passage in WHJSC. We used microarrays to detail the global programme of gene expression underlying cell passage on WHJSC.
Project description:ObjectiveContrary to the long-standing prerequisite of inducing selective (i.e. bifidogenic) effects, recent findings suggest that prebiotic interventions lead to ecosystem-wide microbiota shifts. Yet, a comprehensive characterization of this process is still lacking. Here, we apply 16S rDNA microbiota profiling and matching (GC-MS) metabolomics to assess the consequences of inulin fermentation both on the composition of the colon bacterial ecosystem and fecal metabolites profiles.DesignFecal samples collected during a double blind, randomized, cross-over intervention study (NCT02548247) set up to assess the effect of inulin consumption on stool frequency in healthy adults with mild constipation were analyzed. Fecal microbiota composition and metabolite profiles were linked to the study’s clinical outcome as well as to quality-of-life measurements recorded.ResultsWhile fecal metabolite profiles were not significantly altered by inulin consumption, our analyses did detect a modest effect on global microbiota composition. At the same time, specific inulin-induced changes in relative abundances of Anaerostipes, Bilophila, and Bifidobacterium were identified. The observed decrease in Bilophila abundances following inulin consumption was associated with both softer stools and a favorable change in constipation-specific quality of life measures.ConclusionsEcosystem-wide analysis of the effect of a dietary intervention with prebiotic inulin-type fructans on the colon microbiota revealed that this effect is specifically associated to three genera, one of which (Bilophila) representing a promising novel target for mechanistic research.