Hydrogen-rich jelly attenuates adipose tissue inflammation and metabolic dysfunction in high-fat/high-sucrose...

Molecular hydrogen has been reported to exert antioxidant and anti-inflammatory effects; however, its impact on inflammation and gut microbiota under aging-associated metabolic stress remains unclear. In this study, we investigated the effects of hydrogen-rich jelly (HRJ) in senescence-accelerated mouse prone-8 (SAMP8) mice fed a high-fat/high-sucrose diet (HFHSD). HFHSD feeding induced adipose tissue inflammation, metabolic disturbances, and alterations in gut microbiota composition. Treatment with HRJ suppressed macrophage infiltration into adipose tissue, reduced inflammatory cytokine levels, and restored adiponectin levels. HRJ also partially improved glucose tolerance and metabolic parameters. Gut microbiota analysis revealed that HFHSD was associated with differences in microbial community structure based on beta diversity analysis, whereas HRJ treatment was associated with exploratory changes in specific bacterial taxa and predicted microbial functions, although these changes did not remain significant after FDR correction. These findings suggest that molecular hydrogen attenuates HFHSD-induced metabolic disturbances primarily through suppression of adipose inflammation. Although exploratory changes in gut microbial composition were observed, their biological significance remains unclear and requires further investigation.