Fermented corn germ meal modulates intestinal inflammation and influences gut microbial succession in broiler chickens

ABSTRACT This study explored the effects of fermented corn germ meal (FCGM) on growth performance, inflammatory response, and intestinal microbiota in broiler chickens. A total of 180 one-day-old AA broilers (initial average body weight of 39.16 ± 0.05 g) were randomly divided into three groups: CON group, basal diet; CGM group, basal diet supplemented with 7% corn germ meal (CGM); FCGM group, basal diet supplemented with 7% FCGM. Each group contained 6 replicates with 10 broilers per replicate. The experimental period lasted for 42 d. Compared with unfermented CGM, fermentation significantly increased the contents of crude protein (CP), lactic acid (LA), acetic acid (AA), and propionic acid (PA) ( P < 0.05), while reducing crude fiber (CF) content ( P = 0.036). FCGM had no significant impact on growth performance of broiler chickens ( P > 0.05), but significantly increased cecal AA content at 21 and 42 d ( P < 0.05). Additionally, FCGM modulated the expression of G protein-coupled receptors (GPCRs) and the mitogen-activated protein kinase (MAPK) signaling pathway in cecal tissue, with downregulated relative mRNA expression of ERK and p38 at d 42, and altered inflammatory status via upregulation of the anti-inflammatory cytokine IL-10 relative mRNA expression at d 21 ( P < 0.05). Additionally, FCGM stabilized ileal and cecal microbiota succession. Among these, Firmicutes and Lactobacillus are the dominant bacterial groups, and their abundance showed significant changes over time. Ileal microbiota assembly was dominated by stochastic processes, while cecal microbiota was influenced by both deterministic and stochastic processes. These findings indicate FCGM improves broiler gut health via a metabolite-receptor-microbiota, offering a viable nutritional strategy for antibiotic-free poultry production.