Changes in microbiota composition in colitis-prone mdr1a mice

The symbiotic relationship between gut microbiota and the host is necessary for intestinal homeostasis. Loss of tolerance to the gut microbiota results in chronic inflammatory bowel diseases (IBD), such as Crohn’s disease and Ulcerative colitis. The microbiota resides in two compartments-the gut lumen and mucus layer. Most published findings focus on luminal microbial communities in IBD pathogenesis with much less being understood about the bacteria resident in the mucus layer that abuts the epithelium. Thus, the precise interactions between microbiota and the intestinal mucosa during IBD development are still unknown. To address this, we investigated colitis progression in the mdr1a-/- spontaneous model of colitis. We examined microbiota composition in the mucus and lumen in mdr1a-/- mice and wild-type littermate controls at an early pre-colitic and a later post-colitic stage. We aim to identify if bacterial differences in specific niches precede IBD development and progression. Our study provides valuable insight in microbiota-host interactions in normal and diseased states, revealing new approaches for the management of IBD.