Fucoxanthin extract ameliorates obesity associated with modulation of bile acid metabolism and gut microbiota in high-fat-diet fed mice.

Abstract

Fucoxanthin extract (FX) is a type of carotenoid with a beneficial effect against obesity. The purpose of this study was to explore its precise action mechanism of losing weight. A high-fat diet induced obesity mouse model was established to study the effects of different doses of FX on C57BL/6J male mice for 12weeks. Following intervention, serum indices, tissue sections, liver gene expression, and intestinal microorganisms were analyzed. FX at low, medium, and high dosages (80, 160, and 320mg/kg/day, respectively) for 12weeks was associated with the lower body weight of mice when compared to that of high-fat-diet fed mice. It also improved glucose tolerance as well as serum lipid levels, and reduced fat accumulation. Significant regulation of bile acid metabolism and intestinal microbiota may contribute to the above effects. The bile acids in the FXH group were significantly increased. A low-dose and a medium-dose FX increased the level of transmembrane G protein-coupled receptor 5 (TGR5); a low-dose and high-dose FX increased the farnesoid X receptor (FXR) expression, and a medium-dose had no effect. 16S rRNA sequencing indicated that the Lachnospiraceae and Oscillospiraceae contributed to the beneficial effects of FX. Our study sheds light on mechanisms behind the weight-lowering of FX, and manifested that bile acid metabolism and gut microbiota may be potential therapies. These results support that FX is a valuable candidate for promoting health and alleviating obesity.