Sodium butyrate ameliorates lipid metabolism disorder, intestinal injury, and microbial dysbiosis in broilers under lipopolysaccharide-induced immune stress condition.

Immune stress is a major challenge in the poultry industry, impairing growth, liver metabolism, and intestinal health. This study investigated whether dietary sodium butyrate (NaBu) could alleviate lipopolysaccharide (LPS)-induced immune stress in yellow-feathered broilers through modulation of the gut-liver axis. A total of 96 male broilers were assigned to a 2 × 2 factorial design with NaBu supplementation and LPS challenge as the main factors. Results showed that NaBu significantly improved growth performance, as reflected by increased average daily gain and average daily feed intake (P < 0.05). NaBu also markedly optimized serum lipid metabolism by decreasing total cholesterol (P < 0.05), and LDL-C (P < 0.05), while increasing HDL-C (P < 0.05). Moreover, NaBu significantly alleviated hepatic inflammation and oxidative injury, evidenced by reduced AST/ALT (P < 0.05) and MDA (P < 0.05) levels and enhanced T-AOC (P < 0.05) and SOD activities (P < 0.05). Intestinal barrier function was also restored, with significant upregulation of Claudin-1, Occludin, ZO-1, and MUC2 in the jejunum (P < 0.05). NaBu also modulated the PPARα/SIRT-1-AMPK signaling pathway, reduced pro-inflammatory cytokine expression, and reshaped the cecal microbiota by increasing beneficial bacteria (e.g., Blautia and Alistipes) and suppressing potential pathogens (e.g., Ruminococcus_torques_group and Escherichia-Shigella). These findings demonstrate that NaBu effectively mitigates LPS-induced immune stress by improving liver function, maintain intestinal homeostasis, supporting its potential as a green feed additive in poultry production.