Effects of Bacillus subtilis on jejunal integrity, redox status and microbial composition of intrauterine growth restriction suckling piglets
Abstract The present study used intrauterine growth restriction (IUGR) piglets as an animal model to determine the effect of Bacillus subtilis on intestinal integrity, antioxidant capacity, and microbiota in the jejunum of suckling piglets. In total, 8 normal birth weight (NBW) newborn piglets (1.62 ± 0.10 kg) and 16 newborn IUGR piglets (0.90 ± 0.08 kg) were selected and assigned to 3 groups. Piglets were orally gavaged with 10 mL sterile saline (NBW and IUGR groups), IUGR piglets were orally gavaged with 10 mL/d bacterial fluid (Bacillus subtilis diluted in sterile saline, gavage in the dose of 2 × 109 colony-forming units per kg of body weight) (IBS group) (n = 8). IUGR induced jejunal barrier dysfunction and redox status imbalance of piglets, and changed the abundances of bacteria in the jejunum. Treatment with Bacillus subtilis increased (P < 0.05) the ratio of villus height to crypt depth (VH/CD) in the jejunum, decreased (P < 0.05) the plasma diamine oxidase (DAO) activity, and enhanced (P < 0.05) the gene expressions of zonula occludens-1 (ZO-1), Occludin and Claudin-1 in the jejunum of IUGR piglets. Treatment with Bacillus subtilis decreased (P < 0.05) the concentration of protein carbonyl (PC), and increased (P < 0.05) the activities of catalase (CAT) and total superoxide dismutase (T-SOD) in the jejunum of IUGR piglets. Treatment with Bacillus subtilis also increased (P < 0.05) gene expressions of superoxide dismutase 1 (SOD1), CAT, and nuclear factor erythroid 2-related factor (Nrf2), as well as the protein expressions of heme oxygenase-1 (HO-1), SOD1, and Nrf2 in the jejunum of IUGR piglets. Treatment with Bacillus subtilis also improved the abundances and the community structure of bacteria in the jejunum of IUGR piglets. These results suggested that IUGR damaged the jejunal barrier function and antioxidant capacity of suckling piglets, altered the abundances of bacteria in the jejunum. Treatment with Bacillus subtilis improved the intestinal integrity and antioxidant capacity, while also improved the abundances and structure of bacteria in the jejunum of suckling piglets.