Aspergillus niger fermented Tartary buckwheat ameliorates obesity and gut microbiota dysbiosis through the NLRP3/Caspase-1 signaling pathway in high-fat diet mice

Abstract

• Fermented Tartary buckwheat dietary fiber was prepared using Aspergillus niger for the first time. • Liquid fermentation improves the content of soluble dietary fiber in Tartary buckwheat. • Liquid fermentation changes the physicochemical properties of Tartary buckwheat soluble dietary fiber, such as water holding capacity, oil holding capacity, water swelling capacity, and cholesterol adsorption capacity. • Fermented Tartary buckwheat dietary fiber has excellent anti-obesity activity. • Fermented Tartary buckwheat dietary fiber regulates the composition of intestinal flora and inhibits obesity in HFD mice. Tartary buckwheat is a popular natural grain commonly used as a functional food in various countries. This study aimed to prepare buckwheat dietary fiber with improved biological activity using liquid fermentation of Aspergillus niger and to elucidate its physicochemical properties and related mechanisms. Compared with unfermented buckwheat dietary fiber, Aspergillus niger fermentation increased the soluble dietary fiber content, thereby improving dietary fiber's physical and chemical properties such as water, oil retention capacity, and swelling cholesterol-binding capacity. Fermented Tartary buckwheat dietary fiber treatment for 14 weeks significantly decreased the hepatic lipid profile, oxidative stress, and protein expression in mice. In addition, fermented Tartary buckwheat dietary fiber intervention could regulate high-fat diet-induced disorders of gut microbiota. These results suggested that fermented Tartary buckwheat dietary fiber has potential “prebiotic” effects in ameliorating obesity.