2′-Fucosyllactose improved muscle health in middle-aged mice performing forced swimming exercise

Abstract

Muscle mass and strength gradually decline from middle age, and appropriate physical activity and exercise habits during this period play a key role in preventing sarcopenia. Exercise is the most effective method for improving muscle health, and consuming appropriate dietary supplements along with exercise can boost its effects. Human milk is the most essential source for muscle growth during infancy, and 2′-fucosyllactose (2′-FL) is most abundant oligosaccharide in human milk. Therefore, we hypothesized that 2′-FL would exhibit muscle protective properties in 10-month-old aged male mice subjected to forced swimming exercises. Our findings revealed that 2′-FL administration significantly improved muscle mass, thickness, and strength of calf muscle compared to forced swimming exercise alone. Additionally, 2′-FL enhanced the hypertrophic changes in gastrocnemius and soleus. Furthermore, 2′-FL upregulated gene expression related to muscle protein synthesis (PI3K, AKT1) and muscle growth (A1R, TRPV4), while inhibiting gene expression related to muscle protein degradation (Atrogin-1, MuRF-1) and muscle growth inhibition (Myostatin, SIRT1). 2′-FL also ameliorated exercise-induced oxidative stress, restored antioxidant enzyme activity, and mitigated muscular cell damage. These findings suggest that 2′-FL may serve as a functional dietary supplement combined with exercise for muscle health.