Ligilactobacillus salivarius alleviated intestinal damage induced by Salmonella in mice via regulating microbiota.

Background: Salmonella is a major foodborne etiological agent with serious drug resistance, and the pursuit of novel therapeutic agents for the prevention and control of Salmonella infections is of paramount significance.

Purpose: This study aimed to investigate the regulatory effects of Ligilactobacillus salivarius (L. salivarius) on intestinal damage in mice infected with Salmonella.

Methods: Thirty healthy, four-week-old ICR mice were divided into three groups: a control group, an infection model group, and a L. salivarius treatment group. Specifically, mice in the treatment group were orally administered L. salivarius for 15 days before being infected with Salmonella. Following a 24-hour post-infection period, samples were collected from the duodenum, jejunum, ileum, cecum, colon, and rectum. These samples were analyzed for bacterial load and histopathological changes, comparing the model and treatment groups. Additionally, rectal contents were subjected to 16 S rRNA and ITS sequencing.

Results: The findings revealed that L. salivarius mitigated the weight loss and organ weight reduction. It also significantly decreased Salmonella counts in the intestinal tract and alleviated the associated intestinal mucosal damage and inflammation. Notably, L. salivarius influenced gut microbiota composition by reducing the abundance of beneficial bacteria such as Coprocola and Acutalibacter, while simultaneously lowering harmful bacterial populations, including Angelakisella, UBA3263, Glomeromycota, Kickxellomycota, Nigrospora, and Fusarium.

Conclusions: Collectively, these findings suggest that L. salivarius protects against Salmonella-induced intestinal damage by reducing bacterial load, mitigating intestinal injury, and modulating gut microbiota composition.