Gut microbiota reconstruction after liver transplantation and its association with early postoperative infections in patients with liver failure

Background Postoperative infection remains a major cause of morbidity after liver transplantation (LT) in patients with liver failure. Increasing evidence suggests that gut microbiota dysbiosis may contribute to infection risk, but its dynamic changes after LT are not fully understood. Methods This retrospective study included 60 patients with liver failure who underwent LT and developed postoperative infection-related risk. Patients were divided into a probiotic group and a non-probiotic group. Fecal samples were collected before transplantation and on postoperative days 7, 14, 21, and 28. Metagenomic sequencing was performed to analyze gut microbial composition, diversity, and antibiotic resistance genes. Results The probiotic group showed a significantly lower rate of postoperative bacterial infection, especially intra-abdominal infection. After LT, gut microbiota gradually recovered in both groups, but restoration was faster in the probiotic group. The non-probiotic group showed persistent dysbiosis, characterized by enrichment of opportunistic pathogens such as Enterococcus and Klebsiella , whereas beneficial genera including Bifidobacterium and Lactobacillus were more abundant in the probiotic group. Antibiotic resistance genes were also more enriched in the non-probiotic group. Conclusion Early postoperative gut microbiota reconstruction is closely associated with infectious complications after LT, and modulation of gut microbiota may help improve postoperative outcomes.