Probiotics Improve Postoperative Adaptive Immunity in Colorectal Cancer Patients: A Systematic Review and Meta-Analysis

There is no consensus on the effect of the probiotics on postoperative adaptive immunity in patients undergoing surgical resection for CRC. We aimed to systematically evaluate the effect of probiotics on postoperative adaptive immunity in perioperative CRC patients. The main end points were postoperative serum IgG, IgA, IgM, CD4⁺ T-cells, CD8⁺ T-cells and CD4⁺-to-CD8⁺ ratio. Meta-analysis was performed with a fixed or random effects model. We included six randomized controlled trials (RCTs) with 492 perioperative CRC patients. The use of enteral probiotics significantly increased the levels of peripheral blood IgG (MD: 1.33; 95% CI: 0.88 - 1.77; I² = 41%), IgA (MD: 0.20; 95% CI: 0.10 - 0.30; I² = 53%), IgM (MD: 0.18; 95% CI: 0.13 - 0.24; I² = 41%), CD4⁺ T-cells (MD: 2.79; 95% CI: 2.34 - 3.24; I² = 0) and CD4⁺-to-CD8⁺ ratio (MD: 0.09; 95% CI: 0.04 - 0.13; I² = 7%). In conclusion, we report that the use of enteral probiotics improves postoperative humoral and cellular immunity in patients with CRC.