Culturing the Chicken Intestinal Microbiota and Potential Application as Probiotics Development

Pure cultures of chicken intestinal microbial species may still be crucial and imperative to expound on the function of gut microbiota, and also contribute to the development of potential probiotics and novel bioactive metabolites from gut microbiota. In this study, we isolated and identified 507 chicken intestinal bacterial isolates, including 89 previously uncultured isolates. Among these, a total of 63 Lactobacillus strains, belonging to L. vaginalis, L. crispatus, L. gallinarum, L. reuteri, L. salivarius, and L. saerimneri, exhibited antibacterial activity against S. Pullorum. Acid tolerance tests showed Limosilactobacillus reuteri strain YPG14 (L. reuteri strain YPG14) has a particularly strong tolerance to acid. We further characterized other probiotic properties of L. reuteri strain YPG14. In simulated intestinal fluid, the growth of L. reuteri strain YPG14 remained stable after incubation for 4 h. The auto-aggregation test showed the auto-aggregation percentage of L. reuteri strain YPG14 was recorded as 15.0 +/- 0.38%, 48.3 +/- 2.51%, and 75.1 +/- 4.44% at 3, 12, and 24 h, respectively. In addition, the mucin binding assay showed L. reuteri strain YPG14 exhibited 12.07 +/- 0.02% adhesion to mucin. Antibiotic sensitivity testing showed that L. reuteri strain YPG14 was sensitive to the majority of the tested antibiotics. The anti-Salmonella Pullorum (S. Pullorum) infection effect in vivo revealed that the consumption of L. reuteri strain YPG14 could significantly improve body weight loss and survival rate of chicks infected by S. Pullorum; reduce the loads of S. Pullorum in the jejunum, liver, spleen, and feces; and alleviate the jejunum villi morphological structure damage, crypt loss, and inflammatory cell infiltration caused by S. Pullorum. Overall, this study may help us to understand the diversity of chicken intestinal microflora and provide some insights for potential probiotic development from gut microbiota and may find application in the poultry industry.