Ligilactobacillus salivarius AR809 and its exopolysaccharides mitigate antibiotic-induced gut dysbiosis and restore intestinal barrier function

Abstract Gut microbiota dysbiosis is closely associated with intestinal barrier dysfunction and immune imbalance. This study evaluated the efficacy of Ligilactobacillus salivarius AR809 and its exopolysaccharides (EPS809) in alleviating dysbiosis-associated intestinal dysfunction. In an antibiotic-induced murine model, both viable AR809 cells and EPS809 significantly improved intestinal barrier integrity and immune status. While viable AR809 showed stronger effects, EPS809 also produced significant improvements and similar protective trends, supporting the view that EPS809 may contribute importantly to the overall benefits. Both interventions reduced intestinal permeability, enhanced mucosal immune factors such as secretory IgA, and attenuated histopathological damage. They further helped restore microbiota composition toward that of the healthy state (as evidenced by β-diversity), along with recovery of functional taxa at the family and genus levels. Correlation analyses indicated that these benefits may involve modulation of microbial metabolites, although this remains speculative and warrants future validation. Collectively, the results suggest that AR809 and EPS809 may support recovery of gut microbial balance and intestinal function in antibiotic-challenged mice. Further studies with deeper exopolysaccharide characterization and mechanistic validation are warranted.