Integrative Multi‑omics Analysis of Lipid Metabolism During the Growth and Development of Qiandongnan Xiaoxiang Chickens Based on the Gut‑Muscle Axis

The distinctive flavor and desirable texture of Qiandongnan Xiaoxiang chicken meat make it an ideal model for studying the formation of chicken meat quality traits. This study investigated age-related changes in meat quality, gut microbiota, and the underlying molecular mechanisms in Qiandongnan Xiaoxiang chickens. By integrating multi-omics data, we systematically examined the alterations and interrelationships among serum biochemical indices, gut microbial composition, breast muscle metabolome, and transcriptome in chickens at different ages (60-180 days). The results showed that increasing age significantly affected physiological metabolism, muscle development, and meat quality formation. As age increased, breast muscle pH, shear force, and redness (a*) increased, whereas yellowness (b*) decreased. Serum lipidomic profiling revealed elevated levels of triglycerides, cholesterol, and free fatty acids, accompanied by a reduction in high-density lipoprotein cholesterol. Flavor precursors such as sucrose, arbutin, acylcarnitines, lipid-derived substrates, and bile acid–related metabolites may participate in the Maillard reaction, lipid oxidation, or undergo further transformation during processing, thereby promoting aroma formation. With increasing age, lipid metabolism-related signaling pathways, including adipocytokine signaling, fatty acid biosynthesis, fatty acid metabolism, linoleic acid metabolism, glycerophospholipid metabolism, and regulation of lipolysis in adipocytes, were significantly enriched. Transcriptomic analysis identified the key lipid-related gene PLA1A , whose expression pattern was consistent with the observed metabolic changes. Multi-omics analysis identified gut microorganisms ( Bifidobacterium, Lachnospiraceae NK4A136 group , and Christensenellaceae R7 group ) that were negatively correlated with the PLA1A gene and flavor metabolites such as 4‑aminovaleric acid betaine, danazol, and hetisine. Collectively, these findings elucidate the microbial–metabolic–genetic network underlying meat quality development and provide new insights for optimizing poultry production.