Published online Mar 26, 2020. doi: 10.4252/wjsc.v12.i3.188
Peer-review started: November 4, 2019
First decision: December 6, 2019
Revised: December 12, 2019
Accepted: February 17, 2020
Article in press: February 17, 2020
Published online: March 26, 2020
Core tip: In healthy individuals, Paneth cells restrict the overgrowth of commensal bacteria in the gut while killing luminal pathogenic bacteria by secreting antimicrobial peptides. Such a property protects crypt intestinal stem cells against bacterial infection, thus ensuring epithelial homeostasis in steady state. Among the active pool of intestinal stem cells, apoptosis commonly occurs as a result of ionizing irradiation. Nevertheless, the intestinal epithelium will recover its integrity after sublethal irradiation. On this basis, the mechanism by which Paneth cells provide growth signals for intestinal stem cells to facilitate epithelial regeneration is easy to understand, whereas the automatic recovery of irradiated intestine from sublethal irradiation is perplexing. Being challenged with luminal bacteria, the degranulation of Paneth cells can be stimulated in a cholinergic- or inflammatory-substance-dependent manner. Then, Paneth cells can perform an antibacterial function that influences the inflammatory milieu in irradiated intestine. Therefore, radiation-induced intestinal bacterial dysbiosis can be managed.