Fig. 2

Influence of commensals on maturation of the vascular and immune system. Sketch shows crypts, blood vessels, C. rodentium and neutrophils under different colonization conditions. GF mice have an immature colon and when infected with C. rodentium, they become lifelong carriers with high pathogen titers and low numbers of neutrophils in the colon. Colonization of GF animals with the OMM¹² microbiota prior to C. rodentium infection leads to partial maturation of the colonic blood vessels and crypts. Furthermore, OMM¹² colonization activates endothelial cells allowing neutrophils to extravasate into the lamina propria and lumen of the colon, with partial elimination of C. rodentium. Addition of MC² to the OMM¹² consortium further enhances tissue maturation of the colon allowing clearance of C. rodentium comparable to SPF mice