Galacto-oligosaccharides and xylo-oligosaccharides affect meat flavor by altering the cecal microbiome, metabolome, and transcriptome of chickens

Studies have shown that prebiotics can affect meat quality; however, the underlying mechanisms remain poorly understood. This study aimed to investigate whether prebiotics affect the flavor of chicken meat via the gut microbiome and metabolome. The gut content was collected from chickens fed with or without prebiotics (galacto-oligosaccharides or xylo-oligosaccharides) and subjected to microbiome and metabolome analyses, whereas transcriptome sequencing was performed using chicken breast. Prebiotic supplementation yielded a slight improvement that was not statistically significant in the growth and production performance of chickens. Moreover, treatment with prebiotics promoted fat synthesis and starch hydrolysis, thus increasing meat flavor by enhancing lipase and α-amylase activity in the blood of broiler chickens. The prebiotics altered the proportions of microbiota in the gut at different levels, especially microbiota in the phyla Bacteroidetes and Firmicutes, such as members of the Alistipes, Bacteroides, and Faecalibacterium genera. Furthermore, the prebiotics altered the content of cecal metabolites related to flavor substances, including 8 types of lysophosphatidylcholine (lysoPC) and 4 types of amino acid. Differentially expressed genes (DEGs) induced by prebiotics were significantly involved in fatty acid accumulation processes, such as lipolysis in adipocytes and the adipocytokine signaling pathway. Changes in gut microbiota were correlated with metabolites, for example, Bacteroidetes and Firmicutes were positively and negatively correlated with lysoPC, respectively. Finally, DEGs interacted with cecal metabolites, especially meat-flavor-related amino acids and their derivatives. The findings of this study integrated and incorporated associations among the gut microbiota, metabolites, and transcriptome, which suggests that prebiotics affect the flavor of chicken meat.