To estimate the efficacy of pro-/synbiotics treatment in patients undergoing colorectal resection, a meta-analysis of randomized controlled trials was conducted.

An electronic search of PubMed, MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Academic Search Premier, and China National Knowledge Infrastructure was performed, and RevMan 5.0 was used for statistical analysis.

Six studies including 361 patients undergoing elective colorectal surgery were retrieved. The combined analysis revealed that perioperative pro-/synbiotics administration had a positive effect on the incidence of diarrhea (OR 0.29, 95% CI 0.14 to 0.62, P=0.001), the incidence of symptomatic intestinal obstructions (OR 0.39, 95% CI 0.19 to 0.78, P=0.008), the incidence of operative total infections (OR 0.39, 95% CI: 0.22 to 0.68, P=0.0010), and pneumonia infection (OR 0.32, 95% CI 0.11 to 0.93, P=0.04). The regimen increased the numbers of Lactobacillus (MD 2.66, 95% CI: 2.13 to 3.18; P<0.00001), and decreased the counts of Enterobacteriaceae (MD –1.52, 95% CI: –1.93 to –1.11, P<0.00001). No significant differences were found between the two groups in septic morbidity, incision infection, perineal infection, intraabdominal infection, anastomotic leak, the first defecation time, length of hospital stay, mesenteric lymph nodes for bacterial translocation. No mortality related to pro-/synbiotics treatment was revealed in all studies.

Based on the meta-analysis, perioperatively use pro-/synbiotics as prophylaxis in patients undergoing colorectal resection improved clinical outcomes. The best preventive strategy (including species and the optimal dose) of pro-/synbiotics should be considered in future meta-analyses.