Lactobacillus reuteri DSM 17938 Improves Intestinal Motility in Mice With Postoperative Ileus by Modulating Gut Microbiota and Macrophage

BACKGROUND: Postoperative ileus (POI) is a common complication after abdominal operation, which is characterized by delayed gastrointestinal motility that can lead to prolonged hospitalization. Previous studies have demonstrated that gut microbiota and macrophages are involved in POI pathogenesis, but the underlying mechanism and the role of probiotics in it are still unclear. This work investigated the prophylactic effect of Lactobacillus reuteri (L. reuteri) DSM 17938 administration on POI mice. METHODS: Mice were supplemented with antibiotics or L. reuteri DSM 17938 for two weeks before intestinal manipulation surgery. One day after surgery, the small intestine transit rate was evaluated. Samples were collected to determine the intestinal macrophages, histology, cytokines, gut microbiota, and fecal metabolome. KEY RESULT: macrophage, reduced M1 macrophage, and modulated macrophage-associated cytokines. Additionally, L. reuteri DSM 17938 slightly alleviated gut metabolic disorders but had an effect on a portion of metabolites of fecal tryptophan metabolism, modulated gut microbiota composition and function, and specifically suppressed bacterial invasion of epithelial cells and the expansion of Escherichia coli, which had a negative correlation with the small intestine transit rate in POI mice. CONCLUSIONS AND INFERENCES: Our findings indicate that L. reuteri DSM 17938 is a promising probiotic for the prevention of POI, but it still needs further clinical validation.