Lactobacillus fermentum 1.2133 display probiotic potential in vitro and protect against Salmonella pullorum in chicken of infection

The efficacy of Lactobacillus as an antibiotic substitute has been investigated as one of the potential strategies to prevent Salmonella infection in poultry. The purpose of this study was to explore the antibacterial activity of Lactobacillus fermentum 1.2133 (Lact. fermentum 1.2133) against Salmonella pullorum CVCC533 (Salm. pullorum CVCC533) and its effect on chickens infected with Salm. pullorum CVCC533. Results showed that Lact. fermentans 1.2133 has antibacterial activity against Salm. pullorum CVCC533 and the cell-free fermentation supernatant of Lact. fermentum 1.2133 had a bactericidal effect on the bacteria in the Salm. pullorum CVCC533 biofilm by significantly reducing the number of Salmonella and aerobic bacteria in the chicken duodenum, ileum, and cecum, including Escherichia shigella (P < 0.05), improved the species abundance of Lactobacilli (P < 0.05). The damage to the chicken intestine by Salm. pullorum CVCC533 was reduced as the expression of avian beta-defensin 2 (AvBD2) mRNA in chicken small intestine was increased (P < 0.05). The results showed that Lact. fermentum 1.2133 had the potential to be a probiotic for poultry due to its regulation of intestinal AvBD2 mRNA as well as its intestinal flora.