Introduction: Interstitial Cells of Cajal (ICC) act as pacemakers for gastrointestinal (GI) motility. However, their relationship with gut microbiota remains unclear. This study aimed to elucidate the effects of gut microbiota on ICC homeostasis.
Methods: Mice were given water dissolved with an antibiotic (ABX) cocktail for 4 weeks to eliminate the gut microbiota. After the administration period, the ileum was collected from the mice for various examinations.
Results: ABX treatment significantly reduced GI transit. However, no changes were observed in the spontaneous contraction frequency of the ileum. The area of the c-Kit+ ICC network significantly decreased in the ABX-treated group, and a similar trend was observed in germ-free mice. Supplementation with short-chain fatty acids did not inhibit the reduction in c-Kit+ ICC induced by ABX treatment. On the other hand, serotonin supplementation significantly inhibited the reduction in c-Kit+ ICC caused by ABX administration. The number of ICCs expressing the proliferation marker decreased in the ABX-treated group.
Summary: The results suggest that gut microbiota regulates the homeostasis of ICC through serotonin. The maintenance of serotonin levels in GI tract by gut microbiota may promote ICC proliferation.