Benefits of <i>Monascus anka</i> solid-state fermentation for quinoa polyphenol bioaccessibility and the anti-obesity effect linked with gut microbiota

Abstract

In our previous study, a polyphenol-utilization targeted quinoa product was developed <i>via</i> solid-state fermentation with <i>Monascus anka</i>. In this study, we investigated the polyphenol-related novel functions of the fermented product further. Compared with unfermented quinoa, <i>M. anka</i> fermented quinoa alleviated the trapping effect of the macromolecules, especially in the colonic fermentation stage, resulting in enhanced polyphenol bioaccessibility. <i>Lachnoclostridium</i>, <i>Megasphaera</i>, <i>Megamonas</i>, <i>Dialister</i>, and <i>Phascolarctobacterium</i> might contribute to polyphenol liberation and metabolism in fermented quinoa. Additionally, fermented quinoa polyphenols presented an efficient anti-obesity effect by enhancing hepatic antioxidant enzyme activities, suppressing fatty acid synthesis, accelerating fatty acid oxidation, and improving bile acid synthesis. Moreover, fermented quinoa polyphenol supplementation alleviated gut microbiota disorder induced by a high-fat diet, resulting in a decreased ratio of <i>Firmicutes</i>/<i>Bacteroidota</i>, and increased relative abundances of <i>Lactobacillus</i> and <i>Lachnoclostridium</i>. The obtained results suggested that the principal anti-obesity effect of fermented quinoa polyphenols might act through the AMPK/PPAR<i>α</i>/CPT-1 pathway. In conclusion, <i>M. anka</i> solid-state fermentation effectively enhanced the bioaccessibility of quinoa, and the fermented quinoa polyphenols showed considerable anti-obesity effect. Our findings provide new perspectives for the development of dietary polyphenol-based satiety-enhancing functional foods.