Microbiota-mediated naringenin release limits postoperative acute gastrointestinal injury by suppressing ferroptosis

Acute gastrointestinal injury (AGI) remains a major complication after cardiopulmonary bypass, yet its microbiome-related determinants are unclear. We identify microbiota-mediated naringenin (NAR) release as a candidate modulator of AGI susceptibility. Patients who subsequently develop AGI have lower preoperative fecal NAR levels and β-glucuronidase (GUS) activity, accompanied by reduced abundance of Bacteroides vulgatus (B. vulgatus). In germ-free and conventional mice, B. vulgatus alleviates intestinal ischemia-reperfusion injury through GUS-dependent release of NAR from its glucuronide conjugate. Mechanistically, NAR engages the TLR4/MyD88-SPRR2A axis to suppress CHAC1-driven ferroptosis, thereby maintaining epithelial integrity and promoting mucosal repair in vivo and in organoids. Clinically, preoperative fecal NAR concentration and GUS activity show exploratory value as noninvasive markers for postoperative AGI risk stratification. Collectively, these findings support a microbiota-host metabolic model in which microbial NAR release may mitigate postoperative gastrointestinal injury by restricting ferroptosis, with potential implications for risk assessment and therapeutic modulation.