Muscle aging amelioration by yeast protein supplementation was associated with gut microbiota

Abstract

• Yeast protein improved muscle histologically and ultrasonically and increased myofiber size. • Yeast protein promoted muscle protein synthesis and muscle regeneration and differentiation. • The composition and diversities of gut microbiota were altered by yeast protein. • Yeast protein-induced gut microbiota changes were closely involved in the process of muscle aging. There may be close links among yeast protein (Saccharomyces cerevisiae) supplementation, gut microbiota and skeletal muscle aging. In present study, nineteen-month-old mice received yeast protein (1.0 g/kg/d) for three months by gavage. Histological and ultrasonographical improvements in muscle as well as an increase in myofiber size were observed after yeast protein supplementation. Moreover, yeast protein activated Akt/mTOR/4E-BP1 pathway and regulated myogenic regulatory factors (Myog, Myf4, Myf5, and Myod1) to promote muscle protein synthesis and muscle regeneration and differentiation. Meanwhile, alpha and beta diversities as well as the ratio of Firmicutes and Bacteroidetes were elevated after yeast protein supplementation. Changes in the abundance of gut microbiota after yeast protein supplementation were significantly correlated with glycan biosynthesis and metabolism, amino acid metabolism and lipid metabolism, closely involved in the process of muscle aging. Hence, yeast protein supplementation could contribute to ameliorating muscle aging, which may be associated with gut microbiota.