OBJECTIVE  To investigate the risk factors for intra-abdominal infection after liver transplantation and analyze the preventive effect of perioperative intestinal microecological intervention.

METHODS  A total of 196 patients who underwent liver transplantation at the Liver Transplantation Center, Department of Hepatobiliary Surgery, the First Affiliated Hospital of Air Force Medical University from Jan. 2020 to Jun. 2025 were included in this study. They were divided into an intervention group and a control group based on a random number table, with 98 cases in each group. The intervention group received intestinal microecological intervention during the perioperative period, while the control group received conventional treatment. The intestinal flora structure, inflammatory response and oxidative stress were analyzed and compared between the two groups one day before liver transplantation and on the 15th day after surgery. The incidence of postoperative intestinal bacterial translocation and intra-abdominal infection in the two groups was observed. Meanwhile, the patients were divided into an infected group （n=37） and a non-infected group （n=159） according to their postoperative intra-abdominal infection status. Logistic regression analysis was used to identify the risk factors for intra-abdominal infection after liver transplantation, and the receiver operating characteristic （ROC） curve was plotted to evaluate the predictive value.

RESULTS  On the 15th day after surgery, the counts of Escherichia coli, Enterococcus faecalis and Staphylococcus aureus in the intestinal tract of the intervention group were lower than those in the control group （P＜0.05）, while the counts of Clostridium leptum, Bifidobacterium and Lactobacillus in the intervention group were higher than those in the control group （P＜0.05）. On the 15th day after surgery, the levels of C-reactive protein, tumor necrosis factor-α, malondialdehyde and serum lipid peroxides in the intervention group were lower than those in the control group （P＜0.05）. The incidence of bacterial translocation in the intervention group was 12.24% （12/98）, which was lower than 23.47% （23/98） in the control group（P＜0.05）. The incidence of bacterial translocation and intra-abdominal infection in the intervention group was 8.16% （8/98）, which was lower than 29.59% （29/98） in the control group at （P＜0.05）. A preoperative Model for End-Stage Liver Disease （MELD） score （≥20 points） （OR=2.331） and ascites （OR=3.358） were risk factors for intra-abdominal infection after liver transplantation （P＜0.05）, while intestinal microecological intervention （OR=0.219） and a high prognostic nutritional index （OR=0.927） were protective factors against intra-abdominal infection after liver transplantation （P＜0.05）. The area under the curve for combined detection of the above markes was 0.826, with a sensitivity of 0.649 and a specificity of 0.855.

CONCLUSIONS  Intestinal microecological intervention after liver transplantation can improve postoperative intestinal flora imbalance, alleviate inflammation and oxidative stress responses to a certain extent, reduce the incidence of intestinal bacterial translocation and intra-abdominal infection. The intervention measures can be implemented based on risk factors to reduce the risk of infection.