Effects of probiotics on postoperative inflammation, gut microbiota, and clinical outcomes in patients with colorectal cancer: a systematic review and meta-analysis

Abstract

Background Perioperative probiotics for CRC surgery may modulate gut microbiota, yet evidence for inflammation, complications is inconsistent. We systematically assessed these outcomes. Methods Following PRISMA guidelines, we searched PubMed, Embase, Cochrane Library, and Web of Science for randomized controlled trials (RCTs). A random‐effects model was applied. Results Probiotics reduced interleukin‐6 (MD: −7.52, 95% CI: −14.18 to −0.86; P = 0.03) and white blood cell count (MD: −1.18, 95% CI: −1.90 to −0.46; P = 0.001), but not C‐reactive protein. Incidence of infectious complications lowered: pneumonia (OR: 0.41, 95% CI: 0.25 to 0.68; P = 0.0005), urinary tract infection (OR: 0.40, 95% CI: 0.18 to 0.88; P = 0.02), surgical site infection (OR: 0.54, 95% CI: 0.39 to 0.74; P = 0.0002), bacteremia (OR: 0.37, 95% CI: 0.16 to 0.86; P = 0.02), and septicemia (OR: 0.27, 95% CI: 0.13 to 0.57; P = 0.0007). Probiotics also shortened postoperative pyrexia duration (MD: −0.89, 95% CI: −1.32 to −0.47; P<0.001) and cumulative antibiotic therapy (MD: −1.42, 95% CI: −1.80 to −1.03; P<0.001). Gut microbiota analysis showed increased Bifidobacterium (MD: 1.38, 95% CI: 0.31 to 2.45; P = 0.01) and decreased Enterobacteriaceae (MD: −1.41, 95% CI: −2.11 to −0.71; P<0.001). Intestinal barrier function improved, with reduced bacterial translocation (OR: 0.24, 95% CI: 0.07 to 0.88; P = 0.03) and lower serum zonulin (MD: −0.81, 95% CI: −1.03 to −0.58; P<0.001). Non‐infectious symptoms including diarrhea (OR: 0.38, 95% CI: 0.25 to 0.57; P<0.001) and abdominal distension (OR: 0.53, 95% CI: 0.33 to 0.83; P = 0.006) were reduced. Clinical recovery accelerated: shorter hospital stay (MD: −1.06, 95% CI: −1.69 to −0.43; P = 0.001), earlier first flatus (MD: −0.41, 95% CI: −0.70 to −0.12; P = 0.005), first defecation (MD: −0.83, 95% CI: −1.52 to −0.15; P = 0.02), and faster fluid diet tolerance (MD: −0.28, 95% CI: −0.41 to −0.15; P<0.001).Anastomotic leak was not significantly reduced (OR: 0.61, 95% CI: 0.32 to 1.14; P = 0.12). Conclusion Perioperative probiotic supplementation in CRC patients may reduce postoperative inflammation, lower infectious complication rates, improve gut microbiota composition and intestinal barrier function, alleviate non‐infectious symptoms, and accelerate clinical recovery. Notwithstanding these observed benefits, pooled results should be interpreted with extreme caution because of substantial heterogeneity. Systematic Review Registration https://www.crd.york.ac.uk/PROSPERO/view/CRD420261379777 , identifier CRD420261379777.