Kimchi Probiotic Weissella cibaria Wikim0187 Attenuates Age-Related Muscle Loss: Association with Gut Microbiota...

Sarcopenia, characterized by an age-related progressive decline in skeletal muscle mass and strength, is emerging as a major public health concern in aging societies. Despite growing insights into sarcopenia pathophysiology, effective and targeted therapeutic strategies for preventing or treating age-related muscle loss remain limited. Here, we aimed to examine the effects of Weissella cibaria Wikim0187, a probiotic strain isolated from kimchi, on age-related sarcopenia. Male C57BL/6J mice aged 18 months received oral administration of Wikim0187 (1 × 10⁹ CFU per mouse) for 4 months. Wikim0187 supplementation induced significant increases in gastrocnemius muscle mass and quadriceps muscle mass, absolute grip strength, and mean muscle fiber cross-sectional area. At the molecular level, MuRF-1 and Atrogin-1 expression was substantially reduced, whereas that of MyoD and Myogenin was markedly elevated, particularly in the quadriceps muscle. Western blot analysis confirmed a reduction in Atrogin-1 protein levels and an increase in phosphorylated Akt. In addition, gut microbiota analysis revealed significant alterations in microbial composition, with positive correlations between enriched bacterial taxa and improved clinical parameters. Taken together, these findings support the therapeutic potential of Wikim0187 as a safe and effective intervention for the prevention and treatment of sarcopenia in elderly populations.