Commensal gut bacteria benefit their host in many ways, for instance by aiding digestion and producing vitamins. In this study  the authors report that commensal bacteria can promote intestinal epithelial renewal in both flies and mice. Interestingly, among commensals this effect is most specific to Lactobacilli. Lactobacilli stimulate NADPH oxidase (dNox/Nox1)-dependent ROS production by intestinal enterocytes and thereby activate intestinal stem cells. This means that nutrients for example fibre may alter intestinal epithelial renewal. A interesting prospect.

Patell  PH et al  (2013) Stimulating cROSstalk between commensal bacteria and intestinal stem cellsThe EMBO Journal 32, 3009 – 3010 .