Effect of Perioperative Glutamine-Enhanced Parenteral Nutrition on Short-Term Outcomes in Colorectal Cancer Patients Undergoing Radical Resection: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BackgroundParenteral glutamine (Gln) supplementation can enhance the immune function of patients with colorectal cancer(CRC), regulate inflammatory response, nitrogen balance and protein synthesis, reduce the morbidity of postoperative complications and shorten the length of hospitalization. However, some guidelines and clinical studies have questioned the rationality of using glutamine-containing immunonutrition support in the perioperative period of CRC. Therefore, we conducted a meta-analysis of the effects of perioperative glutamine-enriched parenteral nutrition on short-term postoperative clinical outcomes in patients with CRC.MethodsA comprehensive search of all relevant literature from the default date to June 2025 was performed using the following databases: PubMed, Embase, Web of Science, Cochrane Library, China Biology Medicine Database (CBM), China National Knowledge Infrastructure (CNKI), VIP Medical Information System (VIP), and Wanfang electronic database. RevMan 5.3 software was used for the meta-analysis. We calculated the outcomes using random- and fixed-effects models.ResultsSeventeen single-center randomized controlled trials (RCTs) involving 950 patients with CRC were included. The control group consisted of 470 patients who received traditional parenteral nutrition therapy and the experimental group consisted of 480 patients who received parenteral nutrition with Gln. The analyses showed that perioperative Gln-enhanced parenteral nutrition reduced the morbidity of infectious complications (Relative Risk [RR]=0.36,95% Confidence Interval [CI]:0.23-0.58) and non-infectious complications (RR=0.27, 95% CI: 0.13-0.55). The length of hospitalization was reduced by 2.18 days (mean difference [MD] = -2.18, 95% CI: -2.59--1.78).ConclusionParenteral Gln supplementation may potentially reduced the morbidity of postoperative complications, shortened postoperative hospitalization, improved some aspects of nutritional status, immune and inflammation function in patients with CRC, based on current evidence of low-to-moderate certainty.