A055: Aerobic Exercise Improves Sarcopenia and Gut-Muscle Axis in ABX-Treated SAMP8 Mice

Sarcopenia, characterized by reduced skeletal muscle mass and function, is a common geriatric condition that impairs mobility and quality of life. Its causes include neuroendocrine dysregulation, chronic inflammation, malnutrition, and gut microbiota imbalance. The gut microbiota influences muscle metabolism and function via the gut-muscle axis, and aerobic exercise has been shown to improve both gut microbiota composition and muscle function. This study explores whether aerobic exercise can alleviate sarcopenia induced by gut microbiota dysbiosis through the gut-muscle axis, offering a basis for exercise interventions. The study employed the senescence-accelerated mouse strain P8 (SAMP8) model. Gut microbiota dysbiosis was induced via a one-week intraperitoneal injection of a broad-spectrum antibiotic cocktail (ABX). Eight-week-old male SAMP8 mice were divided into four groups: control (CON), ABX-treated (ABX), exercise-trained (EXE), and ABX-treated with exercise (ABX+EXE). The EXE and ABX+EXE groups underwent an 8-week aerobic exercise program with progressively increasing intensity. Post-intervention assessments included skeletal muscle mass (quadriceps and gastrocnemius weights), muscle strength (hanging and grip strength tests), muscle fiber type (HE staining and immunohistochemistry), oxidative stress markers (malondialdehyde and superoxide dismutase), gut microbiota composition (16S rRNA sequencing), intestinal barrier function (serum diamine oxidase and D-lactate levels), and neuromuscular junction protein expression (Western blot). Data were analyzed using SPSS 26.0, expressed as mean ± SD, and compared using one-way ANOVA. ABX treatment significantly reduced gut microbiota diversity (P < 0.01), disrupted intestinal barrier function (elevated serum diamine oxidase and D-lactate, P