Lactobacillus gallinarum improves broiler performance by enhancing antioxidant capacity and regulating intestinal microbiota.

The predominant objective in large-scale poultry farming has consistently been to enhance broiler. In this context, the supplementing of probiotics, specifically Lactobacilli, has emerged as a promising strategy to improve production efficiency. Numerous studies have demonstrated that Lactobacilli could modulate intestinal microbiota. To identify effective growth-promoting Lactobacilli, the present study replicated the "high body weight" phenotype of broiler chickens through fecal microbiota transplantation (FMT) and subsequently isolated target strains from FMT recipients exhibiting high body weight. The results demonstrated that Lactobacillus gallinarum CD-13 (CD-13) produced protease and exhibited inhibitory (P < 0.05) effects against pathogenic Gram-positive and Gram-negative bacteria. In vivo experimentation revealed that an average daily gain of broilers in the CD-13 group was increased by 17.72 %, along with enhanced (P < 0.05) duodenal villus height in the CD-13 group compared to the control group (Ctrl). Furthermore, the antioxidant capacity of broilers was improved, as evidenced by elevated levels of catalase (CAT) (P < 0.05) and glutathione peroxidase (GSH-Px) (P < 0.05) in the serum, while the level of malondialdehyde (MDA) was reduced (P < 0.05). 16S rRNA analysis revealed, the CD-13 group exhibited an increase (P < 0.05) in the diversity index of the intestinal microbiota, an elevated Bacteroidota/Firmicutes ratio, and the relative abundance of Bacteroides, whereas a decrease in the relative (P < 0.05) abundance of Alistipes compared with the Ctrl group. In conclusion, CD-13 demonstrated the capacity to enhance broiler growth performance through modulation of the intestinal microbiota and improvement of antioxidant capacity, thereby reducing of intestinal inflammation. The findings of this investigation substantiated the probiotic properties of CD-13 and provided a theoretical foundation for its potential application as a probiotic additive in the poultry industry.