Coated sodium butyrate and vitamin D₃ supplementation improve gut health through influencing intestinal immunity, barrier, and microflora in early-stage broilers

BACKGROUND: Intestinal development and function are critical to maintaining sustained broiler growth. The present study aimed to evaluate the effects of coated sodium butyrate (CSB) and vitamin D-3 (VD3) on the intestinal immunity, barrier, oxidative stress and microflora in early-stage broilers. In total, 192 one-day-old broilers were assigned to a 2 x 2 factorial design including two dietary supplements at two different levels, in which the main effects were VD3 (3000 or 5000 IU kg(-1)) and CSB (0 or 1 g kg(-1)). RESULTS: The results showed that CSB supplementation increased ileal goblet cells (GCs) numbers, villus height and decreased crypt depth in broilers. CSB increased ileal proliferating cell nuclear antigen expression and high-level VD3 decreased cluster of differentiation 3 expression. CSB reduced serum d-lactate, endotoxin (ET), adrenocorticotropic hormone, corticosterone and malondialdehyde (MDA) concentrations and increased total antioxidant capacity (T-AOC) level. Meanwhile, high-level VD3 decreased serum ET concentration. Furthermore, CSB increased ileal T-AOC, lysozyme (LYZ) and transforming growth factor (TGF)-beta and decreased MDA, whereas high-level VD3 decreased ileal MDA and increased secretory immunoglobulin A. CSB up-regulated ileal claudin1, superoxide dismutase 1, TGF-beta and LYZ mRNA expression and down-regulated interleukin-1 beta mRNA expression. CSB combined with high-level VD3 increased ileal Faecalibaculum abundance. Spearman correlation analysis showed that Faecalibaculum was related to the immune and barrier function. CONCLUSION: Dietary supplementation with CSB and high-level VD3 improved early gut health in broilers by promoting intestinal development, enhancing antioxidant capacity, strengthening barrier function and enhancing the favorable composition of the gut bacterial flora. (c) 2024 Society of Chemical Industry.