Paneth Cells Protect against Acute Pancreatitis via Modulating Gut Microbiota Dysbiosis.

Acute pancreatitis (AP) is usually accompanied by intestinal failure, but its mechanism is still unclear. In AP patients, the functions of Paneth cells (lysozyme, HD5, Reg3γ, and Wnt3a) decreased. Compared with AP mice, injuries and inflammation of the pancreas and ileum were aggravated in AP mice treated with dithizone (Dith) (Dith+AP mice). Intestinal permeability and bacterial translocation were also increased. 16S rRNA sequencing showed that the gut microbiota of Dith mice and Dith+AP mice exhibited a marked increase in the pathogenic bacterium Helicobacter and a significant decrease in the probiotic bacterium Blautia. Lysozyme gavage in Dith+AP mice effectively alleviated injuries of the pancreas and small intestine. The beneficial effect of lysozyme was associated with a significant increase in the probiotic bacterium Blautia and a virtual absence of the pathogenic bacterium Helicobacter. The severity of AP in antibiotic-treated mice (ABX mice) was significantly aggravated when receiving feces from Dith mice and was markedly alleviated when receiving feces from lysozyme-gavaged mice. In vitro, lysozyme increased the proliferation of enteroids by promoting the activation of the Wnt pathway and Lgr5 expression in intestinal stem cells. IMPORTANCE We demonstrate that AP patients and experimental AP mice exhibited a dysfunction of Paneth cells. Our in vivo research showed that the severity of AP was exacerbated by the long-term dysfunction of Paneth cells, which was associated with gut microbiota disorder. Restoring part of Paneth cell functions through lysozyme supplementation alleviated the severity of AP and gut microbiota dysbiosis. This study provides novel insight into the link of pancreas-gut interactions in the pathogenesis of AP, providing a new direction for the clinical treatment of intestinal complications during AP.