Lactobacillus Paracasei Combined With Aerobic Exercise Improved Metabolic Dysfunction-associated Fatty Liver Disease In Mice

PURPOSE: To investigate the molecular mechanism of Lactobacillus paracasei combined with aerobic exercise to improve lipid metabolism in MAFLD mice. METHODS: MAFLD mice were induced by high-fat diet and divided randomly into four groups: MAFLD group (M), Lactobacillus paracasei group (ML), aerobic exercise group (MA), and Lactobacillus paracasei combined with aerobic exercise group (MLA). ML and MLA were given Lactobacillus paracasei by gavage (1 × 1010 CFU/kg·BW/d). MA and MLA were trained on the treadmill for 1 hour a day, 5 days a week at 60% VO2max (15 m/min), slope 5°. After 8 weeks of intervention, the liver tissue and blood serum were collected from the mice. Serum TC, TG, LDL-C, and HDL-C were detected by ELISA. The protein expressions of AMPK, pAMPK, SREBP1c, and ACC1 in liver were determined by western blotting. RESULTS: 1. Compared with M, TG, TC, and LDL-C in ML were significantly decreased (3.66 ± 0.80 vs 7.31 ± 1.70 mmol/L, 3.89 ± 0.50 vs 5.55 ± 0.40 mmol/L, 1.75 ± 0.23 vs 2.57 ± 0.16 mmol/L, P < 0.01), and HDL-C was significantly increased (4.29 ± 0.14 vs 3.05 ± 0.15 mmol/L, P < 0.01). TG, TC, and LDL-C in MA were significantly decreased (3.89 ± 0.49 vs 7.31 ± 1.70 mmol/L, P < 0.01, 4.14 ± 0.83 vs 5.55 ± 0.40 mmol/L, 1.84 ± 0.27 vs 2.57 ± 0.16 mmol/L, P < 0.05), and HDL-C was significantly increased (4.58 ± 0.11 vs 3.05 ± 0.15 mmol/L, P < 0.01). TG, TC, and LDL-C in MLA were significantly decreased (1.98 ± 0.67 vs 7.31 ± 1.70 mmol/L, 2.50 ± 0.42 vs 5.55 ± 0.40 mmol/L, 1.39 ± 0.12 vs 2.57 ± 0.16 mmol/L, P < 0.01), and HDL-C was also significantly increased (6.28 ± 0.38 vs 3.05 ± 0.15 mmol/L, P < 0.01). 2. Compared with M, pAMPK/AMPK in MLA was up-regulated 2.35 times (P < 0.01), SREBP1c and ACC1 were decreased by 57.6% and 53.9%. Compared with ML, pAMPK/AMPK was up-regulated by 52.2%, SREBP1c and ACC1 were decreased by 31.5% and 16.3% in MLA. Meanwhile, Compared with MA, pAMPK/AMPK was up-regulated by 34.9%, SREBP1c and ACC1 were decreased by 38.9% and 21.1% in MLA. CONCLUSION:Lactobacillus paracasei combined with aerobic exercise may activate AMPK pathway and down-regulate the expression of SREBP-1c and ACC1 to improve liver lipid metabolism in MAFLD mice. Supported by the Natural Science Foundation of Shandong Province (ZR2020MC018), Shandong Province graduate education quality curriculum construction project (SDYKC21204).