Subsp. PB200 Improves Intestinal Barrier Function and Flora Disturbance in Mice with Antibiotic-Induced Intestinal Injury.

: Overuse or misuse of antibiotics could cause adverse effects such as gut microbiota dysbiosis and intestinal barrier dysfunction. Probiotic intervention could effectively alleviate these symptoms. However, the precise efficacy of subsp. PB200 ( PB200) in mitigating antibiotic-induced intestinal injury remains unclear. The aim of this study was to systematically evaluate the effects of PB200 on intestinal barrier injury and gut microbiota dysbiosis in a murine model of antibiotic-induced intestinal injury. BALB/c mice were administered ceftriaxone sodium via oral gavage for seven consecutive days, followed by probiotic intervention daily via gastric gavage for 4 weeks. The results indicated that PB200 played a positive role in enhancing intestinal barrier function, as evidenced by the restored intestinal morphology, and elevated the expression of tight junctions including ZO-1, Claudin-4 and Occludin (2.76-fold, 4.39-fold, and 2.61-fold, respectively) compared to that in the Model group. PB200 normalized the levels of serum pro- and anti-inflammatory factors, including IL-1β, IL-6, TNF-α and IL-10, and elevated the diversity and richness of gut microbiota. PB200 significantly elevated the levels of propionic acid and butyric acid, with increases of 1.67-fold and 2.82-fold, respectively, compared to the Model group. Notably, PB200 reduced the abundance of and increased the abundance of , promoting the rebalance of gut microbiota. Taken together, these findings highlighted the significant potential of PB200 in alleviating intestinal barrier damage and restoring the balance of gut microbiota caused by an antibiotic.