OBJECTIVE: To evaluate the effect of perioperative probiotics or synbiotics on the incidence of postoperative infections following major liver surgery. DESIGN: Meta-analysis. DATA SOURCES: PubMed, Embase, Scopus, and the Cochrane Library for relevant English-language studies published up to February 21st, 2024. ELIGIBILITY CRITERIA: Randomized controlled trials evaluating perioperative probiotics or synbiotics for preventing postoperative infections in patients undergoing major liver surgery. DATA EXTRACTION AND SYNTHESIS: Outcomes included postoperative infection incidence, antibiotic therapy duration, length of stay in intensive care unit (ICU) and hospital. A random-effect model was adopted for the meta-analysis. The quality of included studies was evaluated using the Cochrane risk of bias tool. RESULTS: Ten studies involving 588 patients were included. Pooled analyses revealed that perioperative probiotics or synbiotics significantly reduced postoperative infection incidence (RR 0.36, 95% CI [0.24-0.54], CONCLUSIONS: This meta-analysis suggests that perioperative administration of probiotics or synbiotics may reduce the incidence of postoperative infections and duration of antibiotic therapy. Their use as adjunctive therapy during the perioperative period could be considered for patients undergoing major liver surgery.