The association between microbial community and ileal gene expression on intestinal wall thickness alterations in chickens.

The dynamic development of the animal intestine with a concurrent succession of microbiota and changes in microbial community and metabolite spectrum can exert far-reaching effects on host physiology. However, the precise mechanism of mutual response between microbiota and the gut is yet to be fully elucidated. Broilers with varying developmental degrees of intestinal wall thickness were selected, and they were divided into the thick group (H type) and the thin group (B type), using multiomics data integration analysis to reveal the fundamental regulatory mechanisms of gut-microbiota interplay. Our data showed, in broilers with similar body weight, the intestinal morphological parameters were improved in H type and the diversity of microbial communities is distinguishable from each other. The beneficial bacteria such as Bifidobacterium breve was increased whereas avian endogenous retrovirus EAV-HP was decreased in the H type compared with the B type. Furthermore, microbial metabolic potentials were more active, especially the biosynthesis of folate was improved in the H type. Similarly, the consolidation of absorption, immunity, metabolism, and development was noticed in the thick group. Correlation analysis indicated that the expression levels of material transport and immunomodulatory-related genes were positively correlated with the relative abundance of several probiotics such as B. breve, Lactobacillus saerimneri, and Butyricicoccus pullicaecorum. Our findings suggest that the chickens with well-developed ileal thickness own exclusive microbial composition and metabolic potential, which is closely related to small intestinal morphogenesis and homeostasis.