Project description:Here, we report analysis of both the bacterial and host transcriptome as affected by colonization of R. hominis in the mouse gut. Microbial genes required for colonization and adaptation in the murine gut, as well as host genes responding to colonization by this bacterial species, were uncovered.
Project description:Gut function exhibits 24h (circadian) rhythmicity, in part driven by intrinsic clocks within intestinal epithelial cells (IECs). The gut microbiome exhibits 24h rhythms in composition and function, which are important for maintenance of metabolic and immune health. We determined the influence of feeding behaviour on the colonic circadian landscape using an interval feeding paradigm, whereby food intake was partitioned equally across the 24h day. RNAseq analysis revealed that the IEC cell intrinsic clock persists in the absence of diurnal feeding rhythms, however a subset of transcripts lose rhythmicity, demonstrating that feeding driven cell extrinsic temporal cues contribute significantly to maintenance of the rhythmic gut transcriptome. Interval fed mice lost rhythmicity in secretory IgA and within the microbiota and microbial derived short chain fatty acids. This work highlights the importance of daily rhythms in feeding behaviour for maintenance of rhythmic processes within the gut, with implications for metabolic and immune health.
Project description:Background: Humans with metabolic and inflammatory diseases frequently harbor lower levels of butyrate-producing bacteria in their gut. However, it is not known whether variation in the levels of these organisms is causally linked with disease development and whether diet modifies the impact of these bacteria on health. Results: We use germ-free apolipoprotein E-deficient mice colonized with synthetic microbial communities that differ in their capacity to generate butyrate to demonstrate that Roseburia intestinalis interacts with dietary components to (i) impact gene expression in the intestine, directing metabolism away from glycolysis and toward fatty acid utilization, (ii) improve intestinal barrier function, (iii) lower systemic inflammation and (iv) ameliorate atherosclerosis. Furthermore, intestinal administration of butyrate improves gut barrier function and reduces atherosclerosis development. Conclusions: Altogether, our results illustrate how modifiable diet-by-microbiota interactions impact cardiovascular disease, and suggest that interventions aimed at increasing the representation of butyrate-producing bacteria may provide protection against atherosclerosis.
