Effect of intestinal microbiota on the recovery of bowel function for patients undergoing colon surgery: a prospective cohort study

Purpose This study aimed to investigate the risk factors and gut microbiome characteristics influencing postoperative bowel functional recovery in patients undergoing colorectal surgery. Methods Patients who underwent colorectal surgery between January 2023 and October 2023 were stratified into two cohorts based on the timing of their first postoperative defecation (≤ 5 days vs. >5 days). Clinical data were systematically recorded, and identify independent risk factors associated with delayed bowel recovery. Fresh stool specimens were collected postoperatively and subjected to metagenomic sequencing to elucidate the relationship between gut microbiota composition and bowel functional outcomes. Results Thirty-five patients were enrolled in the study. Multivariate analysis identified time to first postoperative enteral feeding ( p  < 0.01) as the independent risk factor for delayed defecation. Alpha diversity indices revealed no significant intergroup differences in microbial species richness. However, patients with prolonged postoperative defecation time (> 5 days) exhibited a reduced proportion of probiotic taxa (e.g., Bifidobacterium, Lactobacillus) and an elevated prevalence of pathogenic bacteria compared to the ≤ 5-day cohort. Metagenomic profiling further demonstrated impaired microbial metabolic pathways in the delayed recovery group, notably diminished carbohydrate metabolism (e.g., glycolysis/gluconeogenesis) and amino acid metabolism (e.g., selenocysteine and taurine biosynthesis). Conclusions Early postoperative resumption of enteral nutrition and probiotic may enhance bowel functional recovery. The observed reductions in microbial-driven gluconeogenesis/glycolysis, selenocysteine, and taurine synthesis suggest that dysregulation of these metabolic pathways may compromise intestinal mucosal repair and homeostasis, contributing to delayed postoperative recovery.