Effect of Lactobacillus acidophilus M6 on Improving Exercise Performance and Relieving Fatigue in Mice

Objective: To isolate Lactobacillus acidophilus M6 from the feces of long-distance runners in the early stage. The aim of this study was to investigate the effect of Lactobacillus acidophilus M6 on improving exercise ability and alleviating fatigue function in mice. Methods: Sixty C57BL/6N male mice were randomly divided into 4 groups: Control, low, medium and high dose groups of L. acidophilus M6, L. acidophilus M6 was given daily for four weeks, muscle strength, exercise endurance, fatigue related indicators, energy related indicators and antioxidant related indicators were measured. Results: The low, medium and high dose of L. acidophilus M6 significantly (P<0.001) improved the forelimb grip strength (124.01±6.02, 132.02±4.30 and 139.66±4.72 g) and exhaustive swimming time (8.03±1.05, 10.06±1.10 and 14.36±0.55 min). The low, medium and high dose of L. acidophilus M6 significantly (P<0.001) reduced the fatigue indexes including the creatine kinase activity (730.66±16.77, 647.66±39.95 and 594.56±32.33 U/L), serum lactic acid (10.13±1.00, 8.36±0.99 and 6.09±0.36 mol/L), serum urea nitrogen (6.40±0.53, 5.96±0.85 and 5.23±0.25 nmol/L) and blood ammonia (115.34±4.50, 99.67±4.50 and 94.33±4.72 μmol/L). L. acidophilus M6 significantly (P<0.001) improved energy metabolism indexes including increasing blood glucose, muscle glycogen and liver glycogen, and significantly (P<0.001) reducing triglyceride content in a dose-dependent manner. L. acidophilus M6 significantly (P<0.001) increased the activity of serum superoxide dismutase, catalase and glutathione peroxidase and decreased the content of malondialdehyde in mice in a dose-dependent manner at the range from 3×10⁷ CFU to 3×10⁹ CFU. Conclusion: L. acidophilus M6 could improve exercise performance and relieve fatigue after exercise in mice by improving the grip strength of forelimbs and the exhaustion swimming time, and increase the indexes related to energy metabolism and antioxidant capacity by decreasing the fatigue indexes such as creatine kinase activity, lactic acid, urea nitrogen and blood ammonia.