As previously described, the caecal ligation and puncture (CLP) method was carried out in mice.33 (link) First, after anaesthetization and disinfection with betadine solution, we performed laparotomy in the abdomen to expose the caecum and the adjoining intestine of mice. Then, a 6.0 thread suture was used to tightly ligate the intestinal canal under the ileocaecal section, puncture the canal wall with a 19-gauge needle, and gently squeeze a small number of intestinal contents into the abdominal cavity to establish a mouse sepsis model. Finally, the mice were subcutaneously injected 1mL saline for post-operative resuscitation. Mice in the sham group underwent laparotomy techniques without ligation and puncture. The ROS scavenger NAC (20 mg/kg) or vehicle was intraperitoneally injected into C57BL/6 mice 1 hour before CLP surgery.