Mulberry leaf and konjac compound powder improves the metabolic capacity of old mice on a high‐protein diet by regulating the structure of the intestinal microbiota

The health of elderly individuals is closely linked to their protein intake and the abundance of intestinal microbiota. To investigate the impact of a compound powder made from mulberry leaf and konjac (hereinafter referred to as 'compound powder') on regulating the structure of intestinal microbiota in 15-month-old BALB/c mice that were fed a high-beef-protein diet, 16S rRNA high-throughput sequencing, reverse transcription quantitative polymerase reaction, western blot, and other biochemical methods were used to analyze the differences in intestinal microbiota, protein metabolism-related genes, short-chain fatty acid (SCFA) content, and serum cytokines.The results showed that the compound powder increased the content of SCFAs, reduced the inflammatory reaction of the body, adjusted the abundance of intestinal microbiota (Firmicutes and Bacteroidetes), and increased the ratio of Firmicutes to Bacteroidetes (F/B). Moreover, the compound powder could increase the abundance of Lactobacillus and some non-dominant bacteria that were related to amino acid metabolism and beneficial to human health, such as Eubacterium coprostanoligenes. These beneficial bacteria competitively reduced the abundance of harmful bacteria to protect the intestinal barrier and promote intestinal health, and upregulated the activities of aminopeptidase, proton-coupled oligopeptide transporter 1, and glutamate dehydrogenase at the transcription and translation levels.The compound powder could balance the abundance of intestinal microbiota, which may improve the metabolic capacity of old mice on a high-protein diet, and ultimately promoting the well-being of elderly individuals. © 2023 Society of Chemical Industry.