A Novel Mixture Containing Enterococcus lactis SF68® Restores Gut Barrier Integrity in a DSS-Induced Murine Model of Post-Colitis IBS-like Symptoms

(1) Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder characterized by abdominal pain and altered bowel habits, linked to dysbiosis and inflammation. Currently available treatments, focused on symptom management, displayed limited efficacy. Recent research highlights microbiota modulation as a potential therapeutic strategy to restore intestinal barrier integrity; (2) A dextran sulfate sodium (DSS)-induced mouse model of post-colitis IBS-like symptoms was performed to evaluate the effect of a novel mixture of Enterococcus lactis SF68 (R), butyrate, and folate. Disease activity index and spleen weight were assessed. Markers of gut inflammation, intestinal barrier alterations, and gut butyrate bioavailability were measured. The activity of colonic mitochondria was also analyzed; (3) Supplementation with the novel mixture significantly reduced spleen weight and cytokine levels. The intestinal epithelial barrier was restored through an increase in claudin-1, occludin, and defensin 1-3 and a reduction in LBP plasma level. Treatment with the mixture enhanced the expression of butyrate transporters in mice. Mitochondrial activity markers, including citrate synthase and Cytochrome c oxidase, were improved by treatment; (4) The novel mixture containing Enterococcus lactis, butyrate, and folate exerted a protective effect against post-inflammatory IBS by reducing local inflammation, restoring intestinal barrier integrity, and enhancing butyrate bioavailability, suggesting its potential for managing post-inflammatory IBS symptoms effectively.