Effects of Gut Microbiota on The Recovery of Intestinal Function After Colorectal Surgery: A Prospective Cohort StudyAuthor information

Abstract Purpose This study aimed to identify risk factors and gut microbiome signatures linked to postoperative gastrointestinal recovery following colorectal surgery. Methods Patients who underwent colorectal surgery from January to October 2023 were categorized into two groups according to their first postoperative defecation time (≤ 5 days) and delayed recovery (> 5 days). Comprehensive clinical variables collected to screen for independent predictors of postponed bowel recovery. Postoperative fresh fecal samples were subjected to metagenomic sequencing to explore associations between gut microbial composition and postoperative gut functional recovery. Results A total of 35 patients were included in the final analysis. Multivariate regression revealed that the initiation time of early postoperative enteral feeding ( p < 0.01) was an independent risk factor for delayed defecation. No intergroup disparities in gut microbial alpha diversity were observed. Relative abundances of beneficial commensal genera including Bifidobacterium and Lactobacillus were significantly depleted, whereas pathogenic bacterial populations were enriched in patients with delayed bowel recovery. Functional metagenomic annotation indicated notable suppression of core microbial metabolic pathways in the delayed-recovery cohort, such as carbohydrate metabolism (glycolysis/gluconeogenesis) and amino acid metabolism (selenocysteine and taurine biosynthesis). Conclusions Early initiation of postoperative enteral nutrition alongside probiotic supplementation may facilitate the restoration of postoperative intestinal function. Downregulation of microbe-mediated glycolysis/gluconeogenesis as well as selenocysteine and taurine biosynthesis likely disrupts intestinal mucosal repair and gut homeostasis, ultimately leading to protracted postoperative gastrointestinal recovery.