Douchi ameliorates high-fat diet-induced hyperlipidaemia by regulation of intestinal microflora in rats

Douchi are good food for obesity prevention, but limited information is known about the potential relationship between hyperlipidaemic effect and intestinal microbiological regulation of Douci. To explore the hyperlipidaemic effect of Douchi fermented by Rhizopus chinensis 12 on hyperlipidaemia rats and the correlation between intestinal flora and hyperlipidaemic effect. The intervention with Douchi significantly (P < 0.05) reduced the levels of total cholesterol, total triglyceride and low-density lipoprotein cholesterol, increased the level of high-density lipoprotein cholesterol, and improved liver damage and fat cell hypertrophy caused by high-fat diet. Douchi also increased the anti- atherosclerosis index and reduced the levels of human oxidized low-density lipoprotein, tumour necrosis factor-alpha, monocyte chemotactic protein-1, C-reactive protein, interleukin-6 and interleukin-1 beta. Furthermore, Douchi regulated the expression of key proteins and significantly (P < 0.05) reversed the decrease in the richness and diversity of the gut microbiota caused by high-fat feeding. The correlation analysis revealed that the relative abundance of Romboutsia was positively correlated with four lipids and inflammatory factors, while that of Lactobacillus, Allobaculum, unidentified_Corynebacterium, Aerococcus, Facklamia, Alcaligenes and unidentified_Clostridiales was negatively correlated. Douchi modulated the activate lipid metabolism and reduced the level of serum inflammatory factors by regulating the balance of the gut microbiota to achieve the anti-hyperlipidaemic effect.