Short-chain fatty acids produced by the gut bacterial fermentation of non-digestible carbohydrates, e.g., fructo-oligosaccharide (FOS), contribute to the maintenance of skeletal muscle mass and oxidative metabolic capacity. We evaluated the effect of FOS ingestion on protein expression of soleus (Sol) and extensor digitorum longus muscles in mice exposed to microgravity (μ-g). Twelve 9-week-old male C57BL/6J mice were raised individually on the International Space Station under μ-g or artificial 1-g and fed a diet with or without FOS (n = 3/group). Regardless of FOS ingestion, the absolute wet weights of both muscles tended to decrease, and the fiber phenotype in Sol muscles shifted toward fast-twitch type following μ-g exposure. However, FOS ingestion tended to mitigate the μ-g-exposure-related decrease in oxidative metabolism and enhance glutathione redox detoxification in Sol muscles. These results indicate that FOS ingestion mildly suppresses metabolic changes and oxidative stress in antigravity Sol muscles during spaceflight.

由肠道细菌发酵不可消化的碳水化合物（例如低聚果糖 (FOS)）产生的短链脂肪酸有助于维持骨骼肌质量和氧化代谢能力。我们评估了 FOS 摄入对暴露于微重力 ( μg ) 的小鼠中比目鱼肌 (Sol) 和趾长伸肌的蛋白质表达的影响。12 只 9 周大的雄性 C57BL/6J 小鼠在国际空间站上以μg或人工1g 的剂量单独饲养，并喂食含或不含 FOS 的饮食（n  = 3/组）。无论 FOS 摄入如何，两块肌肉的绝对湿重都有降低的趋势，并且 Sol 肌肉中的纤维表型在 μ- g 后转变为快收缩型暴露。然而，FOS 摄入倾向于减轻与 μ - g暴露相关的氧化代谢降低并增强 Sol 肌肉中的谷胱甘肽氧化还原解毒。这些结果表明，在太空飞行过程中，FOS 的摄入会轻微抑制反重力溶胶肌肉的代谢变化和氧化应激。