Effects of Adding BCH0 to the Diet on Growth Performance, Tissue Structures, and Gut Microbiota in Broilers.

Studies demonstrated that () as a dietary additive enhanced broiler growth performance, yet its mechanisms of action modulation remained unclear. Therefore, this study investigated effects of dietary BCH0 (1 × 10 CFU/kg) on growth performance, intestinal morphology, gut microbiota, and ileal transcriptomics in Arbor Acres broilers using a completely randomized design. A total of 200 one-day-old broilers were allocated to control (Con, basal diet) and experimental (BCH0, basal diet + 1 × 10 CFU/kg BCH0) groups (10 replicates/group, 10 birds/replicate) over a 42-day trial. The results revealed that BCH0 significantly increased body weights (BW) at 21 and 42 days ( < 0.05), improved the average daily gain (ADG) during the starter (1-21 days) and overall phases (1-42 days), and reduced the ratio of feed intake to body weight gain (F/G) across all phases ( < 0.05). Duodenal morphology analysis indicated a BCH0 elevated villus height (+16.9%, < 0.01) and villus height/crypt depth (V/C) ( < 0.01) and no significant differences in crypt depth ( = 0.46). In the ileum, the BCH0 group exhibited a significantly greater villus height ( < 0.01), crypt depth ( < 0.05), and V/C ( < 0.05) than the Con group. Microbiota analysis revealed no significant differences in α-diversity or β-diversity, but phylum-level shifts involved an increase in and a reduction in in the BCH0 group. At the genus level, dominance shifted from (Control group) to (BCH0 group), accompanied by marked reductions in , , and . Ileal transcriptomics identified 605 differentially expressed genes, with KEGG enrichment highlighting activated nutrient assimilation pathways ( < 0.05), including carbohydrate, mineral, fat, and protein digestion/absorption. These findings collectively demonstrated that BCH0 enhanced broiler growth through the synergistic modulation of beneficial microbiota, the upregulation of nutrient metabolism genes, and intestinal architectural optimization, supporting its role as a sustainable microbial additive for enhancing poultry productivity and gut health.