Fig. 8

Gut microbiota’s influence on gene expression and meat quality. This figure showed the mechanisms of gut-muscle axis regulation mediated by the gut microbiota through its metabolites, which in turn influenced host muscle development and meat quality characteristics. In particular genera (e.g. Romboutsia, Akkermansia, Paeniclostridium, Escherichia-Shigella) and their metabolites (e.g. volatile fatty acids, amino acids) are allowed to enter the host circulatory system via intestinal epithelial transporters (e.g. SLC5 A8, SLC38 A3) to regulate expression of key genes (e.g. METTL21 C, ACOX3, GSTM3, and CYP4 A22) in muscle tissue. This regulatory effect further affected the fatty acid composition (e.g. C16:1, C18:3n6c) and levels of essential amino acids (EAAs) to optimise meat quality. This study revealed a multi-level regulatory network between microorganisms and the host, which provided an important molecular basis for the improvement of livestock production through targeted regulation of intestinal flora. Key mechanisms include: ① Colonic microbial metabolites; ② Differential microbiota expression in the colon; ③ Differentially expressed genes (DEGs) regulating metabolite absorption and transport in colon tissue; ④ Serum biochemical markers; ⑤ DEGs in PM muscle involved in growth and development; ⑥ Differences in meat nutrient composition (Color coding details are available in the Web version)