How Exercise Reshapes Gut Bacteria to Boost Muscle Health
Researchers discovered that exercise trains the microbiome to produce compounds that improve muscle metabolism, opening a new biological pathway for fitness benefits. The finding could reshape how companies develop probiotics and wellness products, and suggests the fitness industry's claims about gut health now have molecular backing.
Originaltitel: Exercise-acclimated microbiota improves skeletal muscle metabolism via circulating bile acid deconjugation
Habitual exercise alters the intestinal microbiota composition, which may mediate its systemic benefits. We examined whether transplanting fecal microbiota from trained mice improved skeletal muscle metabolism in high-fat diet (HFD)-fed mice. Fecal samples from sedentary and exercise-trained mice were gavage-fed to germ-free mice. After receiving fecal samples from trained donor mice for 1 week, recipient mice had elevated levels of AMP-activated protein kinase (AMPK) and insulin growth factor-1 in skeletal muscle. In plasma, bile acid (BA) deconjugation was found to be accelerated in recipients transplanted with feces from trained donor mice; free-form BAs also induced more AMPK signaling and glucose uptake tha n tauro-conjugated BAs. The transplantation of exercise-acclimated fecal microbiota improved glucose tolerance after 8 weeks of HFD administration. Intestinal microbiota may mediate exercise-induced metabolic improvements in mice by modifying circulating BAs. The findings provide novel insights into the prevention and treatment of metabolic diseases.Funding Information: This work was supported by the Japan Society for the Promotion of Science (JSPS) KAKENHI: Grant-in-Aid for Scientific Research (B) (grant numbers 20H04080 and 17H02176) and the Uehara Memorial Foundation.Declaration of Interests: The authors declare no competing interests.Ethics Approval Statement: Animal studies were performed according to the guidelines of the Japanese Council on Animal Care and the Regulations and General Advice of Laboratory Animals of the Swedish Board of Agriculture. All animal experiments were approved by the Committees for Animal Research of Kyoto Prefectural University, Kyoto Prefectural University of Medicine (KPU20200402-R, M25-39) (Kyoto, Japan), and by the Stockholm Ethical Committee (Stockholm, Sweden).