Effect of dietary Bacillus subtilis on basic chemical composition, free amino acids, fatty acids and volatile organic compounds in broiler meat

The aim of this study was to investigate the effect of dietary supplementation with Bacillus subtilis (BS, DSM32324-32325) on the nutritional quality of broiler meat, with emphasis on the content and profile of various chemical components. A total of 144 Arbor Acres male broilers were divided into three dietary treatment groups (CON, control; LBS, 300 mg/kg BS; HBS, 500 mg/kg BS) and fed for 35 days. The results showed that the LBS treatment significantly increased the crude protein content of broiler meat. Dietary BS supplementation increased the content of flavor amino acids (such as serine and alanine) and decreased the content of bitter amino acids such as methionine and isoleucine. Moreover, BS addition reduced the content of saturated fatty acids and increased the content of polyunsaturated fatty acids in broiler meat. Meanwhile, the content of important volatile organic compounds, particularly hexanal, was significantly increased. Finally, tandem mass tags (TMT)-based quantitative proteomics revealed that dietary supplementation with LBS (300 mg/kg BS) favorably affected lipid and amino acid metabolism in broiler meat, and identified key metabolic pathways such as the peroxisome proliferator-activated receptor (PPAR) signaling pathway, amino acid metabolism, and fatty acid degradation. In conclusion, these findings demonstrated that BS supplementation enhanced broiler meat quality by modulating nutrient metabolism pathways.