Tyrosol Ameliorates the Symptoms of Obesity, Promotes Adipose Thermogenesis, and Modulates the Composition of Gut Microbiota in HFD Fed Mice

Tyrosol is one of the main polyphenolic compounds in extra virgin olive oil (EVOO) and its role in combating obesity is unknown. Thus, this study is designed to investigate the effect of tyrosol consumption on obesity and its underlying mechanisms in high-fat diet (HFD)-induced mice.After supplementation with 0.2% (wt/wt) tyrosol for 16 weeks, the final body weight, and the levels of plasma triacylglycerol (TG), total cholesterol (TC), and fasting glucose are significantly decreased when compared with HFD group. Furthermore, tyrosol may act as a ligand which binds with nuclear hormone receptor peroxisome proliferator-activated receptor alpha (PPARα). Uncoupling protein 1 (UCP1), iodothyronine deiodinase 2 (DIO2), PPAR-γ coactivator-1α (PGC-1α), and PR domain containing 16 (PRDM16), the downstream genes of PPARα which are related to thermogenic function of adipocytes, are significantly increased in both brown adipose tissue (BAT) and inguinal white adipose tissue (iWAT) after tyrosol administration. In addition, tyrosol changes the community composition of gut microbiota, including decreasing the ratio of Firmicutes to Bacteroidetes, and increasing the relative abundance of family muribaculaceae, genus Blautia and Lachnospiraceae_bacterium_28_4.Tyrosol consumption attenuates obesity and related symptoms in HFD-fed mice probably via the modulation of PPARα-thermogenesis and gut microbiota.