Gut microbiota controlling radiation-induced enteritis and intestinal regeneration

Cancer remains the second leading cause of mortality, with nearly 10 million deaths worldwide in 2020. In many cases, radiotherapy is used for its anticancer effects. However, radiation causes healthy tissue toxicity as a side effect. In intra-abdominal and pelvic malignancies, the healthy bowel is inevitably included in the radiation field, causing radiation-induced enteritis and dramatically affecting the gut microbiome. This condition is associated with significant morbidity and mortality that impairs cancer patients' and survivors' quality of life. This Review provides a critical overview of the main drivers in modulating the gut microenvironment in homeostasis, disease, and injury, focusing on gut microbial metabolites and microorganisms that influence epithelial regeneration upon radiation injury.