Nobiletin activates thermogenesis of brown and white adipose tissue in high-fat diet-fed C57BL/6 mice by shaping the gut microbiota.

Increasing energy expenditure by activating thermogenesis in brown and beige adipocytes is a critical approach to protect against obesity. Here, we investigated the action and mechanism of a natural polymethoxyflavone on adaptive thermogenesis in high-fat diet-induced obesity mouse model. Nobiletin treatment significantly ameliorated obesity, alleviated the whitening of brown adipose tissue, and promoted browning of white adipose tissue in mice fed a high-fat diet. Gut microbiota analysis and metabolomic profiling revealed that nobiletin treatment resulted in a composition shift in the gut microbiota thereby altering fermentation products acetate levels in the host feces and serum. Further, transplantation of the microbiota from nobiletin-treated mice to microbiota-depleted mice activated brown adipose tissue activity, promoted beige adipocytes formation, and improved high-fat diet-induced obesity. Our results indicate that nobiletin could be used as a dietary therapy to prevent HFD-induced obesity, and provide a potential target-specific gut microbial species-driven mechanism for activating thermogenesis in brown and beige adipocytes.