Fasting primes small intestinal regeneration after damage via a microbiome–metabolite-chromatin axis

Fasting changes the gut microbiome, but how these changes help the body recover from damage is not well understood. We found that fasting increases a helpful bacterium, <i>Akkermansia muciniphila</i> , which produces propionate, which drives epigenetic changes by modifying histones and regulating gene activity. These changes promote the expansion of persister stem cells that help the intestine recover after radiation. This study shows how fasting and gut bacteria work together to protect healthy tissue and suggests that diet or microbial treatments could help reduce side effects of cancer radiotherapy.