Dietary supplementation with capsaicinoids alleviates obesity in mice fed a high-fat-high-fructose diet

Capsaicinoids are the pungent compounds in chili peppers. The present study investigated the effect of capsaicinoids on obesity in mice induced by a high-fat-high-fructose diet. Thirty-two male C57BL/6J mice were randomly divided into four groups (n = 8) and fed one of the following diets, namely, a low-fat diet (LFD), a high-fat-high-fructose diet (HFF), an HFF + 0.015% capsaicinoids (LCP), and an HFF + 0.045% capsaicinoids (HCP), for 12 weeks. Results showed that capsaicinoids significantly reversed HFF-induced obesity. Supplementation with capsaicinoids improved glucose tolerance, reduced plasma lipids, and attenuated inflammation. Capsaicinoids also reduced hepatic lipid accumulation by upregulating the expression of peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α). In addition, capsaicinoids enhanced the production of fecal short-chain fatty acids (SCFAs) and increased the fecal excretion of lipids. Gut microbiota analysis revealed that capsaicinoids decreased the Firmicutes/Bacteroidetes ratio and beneficially reconstructed the microbial community. However, the effects of capsaicinoids on intestinal villus length and lipid tolerance were negligible. In conclusion, capsaicinoids effectively attenuated HFF-induced obesity and metabolic syndrome by favorably modulating lipid metabolism, improving SCFA production, and reshaping gut microbial structure.