Nutrition, Exercise Physiology, and Sarcopenia Laboratory, Jean Mayer USDA Human Nutrition Research Center on Aging (HNRCA), Tufts University, Boston, MA 02111, USA.
Nutrients. 2024 Apr 28;16(9):1323. doi: 10.3390/nu16091323.
Previous studies have identified a role for the gut microbiome and its metabolic products, short-chain fatty acids (SCFAs), in the maintenance of muscle mass and physical function (i.e., the gut-muscle axis), but interventions aimed at positively impacting the gut-muscle axis during aging are sparse. Gut bacteria ferment soluble fiber into SCFAs, and accordingly, to evaluate the impact of a high-soluble-fiber diet (HSFD) on the gut-muscle axis, we fed a whole-food, 3×-higher-soluble fiber-containing diet (relative to standard chow) to aged (98 weeks) C57BL/6J mice for 10 weeks. The HSFD significantly altered gut bacterial community structure and composition, but plasma SCFAs were not different, and a positive impact on muscle-related measures (when normalized to body weight) was not identified. However, when evaluating sex differences between dietary groups, female (but not male) HSFD-fed mice had significant increases for SCFAs, the quadriceps/body weight (BW) ratio, and treadmill work performance (distance run × BW), which suggests that an HSFD can positively impact the gut-muscle axis. In contrast, consistent effects in both male and female HSFD-fed mice included weight and fat loss, which suggests a positive role for an HSFD on the gut-adipose axis in aged mice.
先前的研究已经确定了肠道微生物组及其代谢产物短链脂肪酸（SCFAs）在维持肌肉质量和身体功能（即肠道-肌肉轴）方面的作用，但是针对衰老过程中积极影响肠道-肌肉轴的干预措施却很少。肠道细菌将可溶纤维发酵成 SCFAs，因此，为了评估高可溶纤维饮食（HSFD）对肠道-肌肉轴的影响，我们用全食物、3 倍高可溶纤维含量的饮食（相对于标准饲料）喂养老年（98 周）C57BL/6J 小鼠 10 周。HSFD 显著改变了肠道细菌群落结构和组成，但血浆 SCFAs 没有差异，并且对肌肉相关指标（按体重归一化）没有明显影响。然而，当评估饮食组之间的性别差异时，雌性（而非雄性）HSFD 喂养的小鼠 SCFAs、股四头肌/体重（BW）比值和跑步机工作性能（跑距×BW）显著增加，这表明 HSFD 可以积极影响肠道-肌肉轴。相比之下，在雄性和雌性 HSFD 喂养的小鼠中均出现一致的效果，包括体重和脂肪减少，这表明 HSFD 在老年小鼠的肠道-脂肪轴中发挥了积极作用。
