Effect of Fermented Products Produced by Bacillus licheniformis on the Growth Performance and Cecal Microbial Community of Broilers under Coccidial Challenge

SIMPLE SUMMARY: Coccidiosis is a severe parasitic disease of poultry caused by parasites of the genus Eimeria. Eimeria species infection disrupts the intestinal microbiota of broilers, thereby reducing gut health and growth performance. Continuous use of anti-coccidial drugs leads to the selection of drug-resistant strains of Eimeria. Therefore, developing substitutes for anti-coccidial drugs is an urgent, unmet need. Fermented products produced by Bacillus licheniformis containing probiotics and antimicrobial peptides can modulate the gut microbiota of broilers. However, little is known about the effect of fermented products produced by B. licheniformis on the health, growth, and gut microbial community of broilers exposed to coccidial challenge. In this study, the anti-coccidial and gut microbiota modulatory effect of fermented products produced by B. licheniformis on broilers was evaluated. Results showed that Bacillus licheniformis-fermented product supplementation improved average daily gain at 21 to 35 days of age and regulated the cecal microbial community of broilers exposed to coccidial challenge compared with coccidial challenge alone group. ABSTRACT: This study investigated the effects of fermented products produced by Bacillus licheniformis (fermented products) on the growth performance and cecal microbial community in broilers exposed to coccidial challenge. A total of 108 one-day-old male broiler chicks (Ross 308) were randomly allotted to one of three treatments. Each treatment was distributed into six replicate cages with six birds each. The treatments consisted of a basal diet without treatment (NC), basal diet plus coccidial challenge (PC), and basal diet plus the coccidial challenge and 1 g/kg of fermented products (FP). The results indicated that FP increased the average daily gain of broilers at 21 to 35 days of age compared with the PC group (p < 0.05). The anti-coccidia index in the FP group was elevated compared with the PC group (p < 0.05). Principal coordinate analysis showed significant segregation in bacterial community composition in the cecal digesta among the groups. The genus Lactobacillus was more abundant in the cecal digesta of the FP group compared with the PC group (p < 0.05). There was a positive correlation between the abundance of the genus Lactobacillus in the cecal digesta and growth performance (body weight, average daily gain, and average feed intake). Furthermore, the abundance of the genus Lactobacillus in the cecal digesta was positively associated with the cecal short-chain fatty acid levels (formic acid, acetic acid, propionic acid, butyric acid, and isobutyric acid). These findings suggest that fermented products produced by B. licheniformis can ameliorate the average daily gain of broilers exposed to coccidial challenge. B. licheniformis-fermented product supplementation increases anti-coccidial activity and modulates gut microbiota composition by increasing beneficial microbes and decreasing harmful microbes in broilers under coccidial challenge.