Abstract
This study aimed to investigate the effects of baicalin and chlorogenic acid (BC) on growth performance, intestinal barrier function, antioxidant capacity, intestinal microbiota, and mucosal metabolism in broilers. A total of 720 twenty-one-day-old broilers were randomly allocated into 3 groups, with 6 replicates per group and 40 chickens per replicate. They were fed a basal diet (Con group) or a basal diet supplemented with 250 or 400 mg/kg BC (BC250 and BC400 groups) for 40 consecutive days. The results revealed that 250 mg/kg BC significantly increased 60-d body weight and average daily gain during 39 to 60 d (P < 0.05). Furthermore, Supplementation with 250 mg/kg BC improved the antioxidant capacity and immunity of broilers, as evidenced by increased (P < 0.05) superoxide dismutase and decreased (P < 0.05) malondialdehyde levels in serum and ileum, as well as increased (P < 0.05) immunoglobulin G levels. Supplementation with 250 mg/kg BC enhanced intestinal development by improving intestinal morphology and promoting the proliferation of intestinal crypts. Moreover, Supplementation with 250 mg/kg BC improved (P < 0.05) intestinal permeability, up-regulated (P < 0.05) the expression of tight junction-related genes (Occludin and ZO-1), and down-regulated (P < 0.05) the expression of pro-inflammatory genes (IL-2, IL-8, and IFN-γ). 16S rRNA sequencing revealed significant enrichment of Microbacteriaceae, Micromonosporaceae, Anaerovoracaceae, and Coriobacteriaceae in the BC250 group. Metabolomics showed that 250 mg/kg BC up-regulated the lysosome, foxo signaling pathway, glycosylphosphatidylinositol (GPI)-anchor biosynthesis, and oxidative phosphorylation pathways, while down-regulating the biosynthesis of cofactors pathway. In conclusion, supplementing diets with 250 mg/kg BC is recommended to modulate intestinal microbiota, mucosal metabolism, and antioxidant capacity, thereby improving broiler growth performance and intestinal health.