Molecular mechanism of gut microbiota regulation in skeletal muscle metabolic remodeling and meat quality trait formation in livestock and poultry: a review.

Meat quality is a major determinant of consumer acceptance and economic value, as meat serves as a primary source of high quality protein and essential micronutrients. The formation of meat is a highly complex biological process orchestrated by genetic background, nutritional regulation, and microbial modulation. Recent advances in sequencing technologies and microbiome research have elucidated the regulatory role of the gut microbiota in skeletal muscle metabolism and meat quality via the gut-muscle axis. This review comprehensively synthesizes variations in the gut microbiota of livestock and poultry, highlighting their associations with key meat quality traits such as color, water-holding capacity, tenderness, flavor, and fat deposition. We critically examine how the gut microbiota influences skeletal muscle metabolism and meat formation through the modulation of lipid, glucose, and protein metabolism, alongside muscle fiber characteristics. Furthermore, we review major microbial-derived mediators and signaling pathways integral to gut-muscle crosstalk-specifically short-chain fatty acids, bile acids, amino acids, and vitamins-and discuss how microbial homeostasis or dysbiosis impacts muscle mass and function via inflammatory, oxidative, and hormonal mechanisms. Collectively, these insights clarify potential mechanisms underlying the gut microbiota and muscle axis in animals. Consequently, this review provides a robust theoretical framework for future mechanistic studies and offers practical guidance for developing microbiota-targeted strategies to enhance muscle health and meat quality in livestock and poultry production systems.