Colon gene expression signatures in mice mono-associated with IBD-associated micro-organisms

Studying host-microbiota interactions is fundamental to understand mechanisms involved in intestinal inflammation and inflammatory bowel diseases. In this work, we studied these interactions in mice mono-associated with 4 bacteria and 2 yeasts, all representative of intestinal microbiota and/or associated with IBD pathogenesis: Bacteroides thetaiotaomicron, adhesive-invasive Escherichia coli (AIEC), Ruminococcus gnavus, Roseburia intestinalis, Saccharomyces boulardii and Candida albicans. Transcriptomics analyses showed that B. thetaiotaomicron had the highest immunological effect, being able to almost recapitulate the effects of a whole microbiota, and particularly induced Treg pathways. Furthermore, this analysis also pointed out the effects of E. coli AIEC LF82 on IDO activation and of S. boulardii on angiogenesis, as well as major effects of R. gnavus on metabolism. This work therefore reveals information on the role of each micro-organism and proposes several tracks to follow to better understand IBD pathogenesis and identify therapeutic targets 6 mono-associations + 2 controls (germ-free and conventionalized mice), with 5 to 7 mice per group.