Geranylgeraniol and Green Tea Polyphenols Mitigate Negative Effects of a High-Fat Diet on Skeletal Muscle and the Gut Microbiome in Male C57BL/6J Mice

Natural bioactive compounds are proposed as alternatives in mitigating obesity-associated skeletal muscle dysfunction. The objective of this study was to test the hypothesis that the combination of geranylgeraniol (GGOH) and green tea polyphenols (GTPs) can alleviate high-fat-diet (HFD)-induced muscle atrophy and alter gut microbiome composition. Male C57BL/6J mice fed an HFD were assigned to four groups (12 mice each) in a 2 (no GGOH vs. 400 mg GGOH/kg diet) × 2 (no GTPs vs. 0.5% weight/volume GTPs in water) factorial design. After 14 weeks of diet intervention, skeletal muscle and cecal samples were collected and examined. Compared to the control groups, the group that consumed a combination of GGOH and GTPs (GG + GTPs) had significantly decreased body and fat mass but increased skeletal muscle mass normalized by body weight and cross-sectional area. In soleus muscle, the GG + GTP diet increased citrate synthase activity but decreased lipid peroxidation. Gut microbiome beta-diversity analysis revealed a significant difference in the microbiome composition between diet groups. At the species level, the GG + GTP diet decreased the relative abundance of Dorea longicatena, Sporobacter termitidis, and Clostridium methylpentosum, and increased that of Akkermansia muciniphila and Subdoligranulum variabile. These results suggest that the addition of GGOH and GTPs to an HFD alleviates skeletal muscle atrophy, which is associated with changes in the gut microbiome composition.