Clostridium butyricum regulates visceral hypersensitivity of irritable bowel syndrome by inhibiting colonic mucous low grade inflammation through its action on NLRP6.

Visceral hypersensitivity induced by stress is quite common in irritable bowel syndrome (IBS) patients. Probiotics play an important role in reducing visceral hypersensitivity in IBS patients. However, the mechanism has not been clearly elucidated. In this study, we investigated the role of nod-like receptor pyrin domain-containing protein 6 (NLRP6) in Clostridium butyricum-regulated IBS induced by stress. Our results showed that NLRP6 was down-regulated in IBS group colon tissues. In addition, IL-18, IL-1β, myeloperoxidase (MPO), d-lactic acid (D-LA), and CD172a were up-regulated in the IBS group of colonic mucous. IL-18 and IL-1β were also increased after the NLRP6 gene was silenced. Pathological score suggested low inflammation of colonic mucous rather than terminal ileum. Water-avoidance stress (WAS) showed visceral hypersensitivity to colonic distension. However, treatment with Clostridium butyricum reversed these results, exerting a beneficial effect. In conclusion, Clostridium butyricum may exert a beneficial action on visceral hypersensitivity of IBS by inhibiting low grade inflammation of colonic mucous through its action on NLRP6.