Ningxiang pig-derived Lactobacillus reuteri improves the gut health of weaned piglets by regulating intestinal barrier function and cytokine profiles

Weaning stress in piglets can induce intestinal damage, resulting in impaired growth performance. Probiotics have emerged as significant contributors to enhancing gut health in piglets. This study aimed to evaluate the effects of Lactobacillus reuteri (L. reuteri) supplementation on growth performance, intestinal immunity, and intestinal barrier integrity in weaned piglets. In this investigation, fourteen healthy weaned piglets of similar age and weight, were randomly assigned to two groups (n = 7), receiving either normal saline (Control group) or L. reuteri (L-treatment group) over a 16-day period. The findings revealed no significant impact of L. reuteri on growth performance compared to controls. However, it lowered serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels (P < 0.05) and elevated serum concentrations of Immunoglobulin A (IgA), immunoglobulin G (IgG), and secretory immunoglobulin A (sIgA) (P < 0.05). Additionally, L. reuteri notably enhanced the villus height-to-crypt depth ratio in the ileum (P < 0.05) and increased mRNA expression of zonula occludens-1 (ZO-1), Claudin-1, and ZO-1 in ileal tissue (P < 0.05). Furthermore, L. reuteri reduced mRNA expression of pro-inflammatory cytokines interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) (P < 0.05) in the jejunum and colon while enhancing the expression of the anti-inflammatory cytokine interleukin-10 (IL-10) (P < 0.05) in both the ileum and colon. This study demonstrates that L. reuteri isolated from Ningxiang pigs can improve the intestinal health of weaned piglets by modulating gut barrier function and cytokine levels.