Miso, fermented soybean paste, suppresses high-fat/high-sucrose diet-induced muscle atrophy in mice

Dysbiosis resulting from a high fat/ high sucrose diet (HFHSD) causes sarcopenia by decreasing the production of short-chain fatty acids (SCFAs). This study investigated the effects of miso, a traditional fermented soybean food in Japan, on muscle mass atrophy. Eight week old male C57BL/6J mice were fed HFHSD with or without miso for 12 weeks. A miso diet increased soleus muscle weights (p <0.05) and reduced intraperitoneal glucose tolerance and insulin tolerance (p <0.05). The miso diet downregulated the Tnfa and Cc12 expression, related to inflammation, and Trim63 and Fbxo32 expression, related to muscle atrophy, in the soleus muscle (p <0.05). The miso diet increased SCFA levels, including acetic, propanoic, and butanoic acids, in the feces, serum, and soleus muscle (p <0.05). According to the LEfSe analysis, the miso diet increased family Prevotellaceae, family Christensenellaceae, family Dehalobacterium, family Desulfitibacter; family Deferribacteraceae, order Deferribacterales, class Deferribacteres; and family Gemmatimonadaceae, order Gemmatimonadetes, and class Gemmatimonadales, whereas the miso diet decreased family Microbacteriaceae, order Micrococcales, class Actinobacteria, and family Lactobacillaceae. Miso suppressed HFHSD induced impaired glucose tolerance, low muscle strength, and muscle atrophy by improving dysbiosis and increasing SCFA production and provides new insights into the preventive effects of fermented foods on sarcopenia.