Bacterial-induced Duox-ROS regulates the Imd immune pathway in the gut by modulating the peritrophic matrix

damages the PM during infection. Importantly, we found that gut commensal bacteria ensured proper Duox-dependent ROS production and PM stability, thus preventing Imd pathway overactivation in response to pathogens. We conclude that gut commensal bacteria-induced Duox-ROS is crucial for maintaining PM structural homeostasis, and the PM, in turn, regulates Imd pathway activation and protects intestinal epithelial cells. Thus, our study reveals a crosstalk between the PM barrier and Imd-mediated antibacterial function to ensure host defense in the gut.