Dietary sodium butyrate improves intestinal development and function by modulating the microbial community in broilers.

This study investigated the effects of dietary sodium butyrate (SB) supplementation, provided as a specially coated product, on growth performance, intestinal development, morphological structure and function in broilers. In total, 720 one-day-old Arbor Acres male broilers were randomly allocated into six treatment groups with six replicates each and then fed basal diets (control) supplemented with 0, 200, 400, 800 or 1000 mg/kg of SB or with antibiotics (100 mg/kg aureomycin and 20 mg/kg colistin sulfate). The growth trial lasted for 42 days. No differences (P>0.05) in growth performance were detected between groups during the grower period (1-21 d) or over the total (1-42 d) trial period, whereas the addition of SB improved the intestinal structure by stimulating (P<0.05) goblet cells on jejunal and ileal villi accompanied by a trend towards increased (Pdiets<0.10) ileal villus height. In addition, more inerratic leaf-shaped villi and mucus secretion and significantly fewer erosions were demonstrated by scanning electron microscopy. Apart from decreased (P<0.05) malondialdehyde (MDA) in the ileal mucosa at 21 d of age, supplemental SB at higher doses (800 mg/kg) led to greater (P<0.05) total antioxidant capacity and depressed (P<0.05) MDA concentrations in the jejunal mucosa. Birds fed with 400 mg/kg and 800 mg/kg SB had higher (P<0.05) acetic acid concentrations at 42 d and higher butyric acid at 21 d in the jejunum chyme. Morever, chicks fed SB diet were found to have higher concentrations of butyric acid (P<0.05) in the ileal chyme. SB additions at 400 mg/kg displayed higher Firmicutes and Proteobacteria levels, while a higher (P<0.05) relative abundance of Bacteroidetes was observed at 800 mg/kg. Furthermore, we found a striking decrease in Enterobacteriaceae and increases in Lachnospiraceae and Rikenellaceae in the cecal lumen of birds fed 800 mg/kg SB as well as a higher proportion of Ruminococcaceae and a noticeable reduction (P<0.05) of Lactobacillaceae in birds treated with 400 mg/kg SB. Taken together, our results support the importance of SB in improving the intestinal development, morphological structure and biological functions of broilers through modulation of the microbial community, which seems to be optimized for gut health at higher doses (800 mg/kg) of SB.