Effects of Dietary Bacillus subtilis BC02 Supplementation on Growth Performance, Antioxidant Capacity, and Cecal Microbes in Broilers

This study investigated the effects of Bacillus subtilis BC02 supplementation on broiler performance, antioxidant capacity, and cecal microbes. A total of 288 one-day-old Arbor Acres broilers were randomly divided into three groups. The control group were fed a basal diet, and experimental groups were fed a basal diet supplemented with 250 and 500 mg/kg Bacillus subtilis BC02 (BS250 and BS500), respectively. The results showed that Bacillus subtilis BC02 supplementation increased the average daily feed intake but decreased the feed to gain ratio in broilers from 0 to 14, 0 to 28, and 0 to 42 days. Meanwhile, BS500 significantly decreased triglyceride and serum urea nitrogen levels compared with the control and BS250 groups (p < 0.05). Moreover, diet supplemented with 500 mg/kg Bacillus subtilis BC02 improved the antioxidant capacity by increasing the serum and jejunum levels of superoxide dismutase and glutathione, decreasing that of malondialdehyde and increasing the jejunum mRNA expression of SOD2, CAT, GPX1, and Nrf2 (p < 0.05). Dietary Bacillus subtilis BC02 supplementation increased the villus height, velvet concealed ratio, and the mRNA expressions of IL-2, IL-4, IL-10, and IL-12 (p < 0.05). In addition, the Bacteroidota, Proteobacteria, Helicobacter, and Prevotellaceae UCG-001 were significantly increased (p < 0.05) in the BS500 group. In conclusion, dietary Bacillus subtilis BC02 supplementation can improve the growth performance, antioxidant capacity, and intestinal microflora abundances in broilers.