Cecal microbiota regulates meat quality of Yanshan red jade broilers: insights from metagenomics and targeted metabolomics.

This study aimed to elucidate the molecular mechanism of cecal microbiota regulating muscle flavor in Yanshan red jade broilers with natural body weight variation. Eighteen-week-old hens were selected for this study. Targeted metabolomics was applied to determine the fatty acid and amino acid composition of muscle. Metagenomic sequencing was used to analyze the structure and function of cecal microbial communities. A regulatory network between gut microbiota and meat flavor was constructed via correlation analysis. The results showed that the high-weight female (HF) group had significantly better slaughter performance and leg muscle intramuscular fat (IMF) than the low-weight female (LF) group. Metabolomic analysis identified a total of 38 fatty acids and 25 amino acids. The HF group was enriched in umami amino acids such as arginine and serine, while the LF group had higher content of long-chain polyunsaturated fatty acids (PUFAs) and 1-methyl-l-histidine. Metagenomic analysis showed that Eubacterium and Anaerostipes were the characteristic bacteria in the HF group, while Odoribacter was dominant in the LF group. Functional annotation identified a total of 12 differential metabolic pathways, including core pathways such as lipid metabolism and amino acid synthesis. The association network showed that Eubacterium sp. An11 enhanced growth performance and umami quality by promoting muscle protein deposition, Odoribacter_splanchnicus affected muscle nutritional characteristics by regulating fatty acid metabolism, and Pseudoflavonifractor_capillosus was involved in both growth and flavor regulation. This study provides theoretical support and functional strain targets for flavor improvement of high-quality broilers and precise nutritional regulation of gut microbiota.