Effect of Brown Rice and Whole Wheat on Gut Microbiota and Lipid Metabolism in High-Fat Diet Fed Rats

Abstract

The purpose of this study was to investigate the effect of brown rice and whole wheat on gut microbiota and lipid metabolism. Specific pathogen-free Sprague Dawley (SPF SD) rats were selected and randomly divided into six groups (n = 12 per group): control group, brown rice group, whole wheat group, HFD model group, brown rice + HFD group, and whole wheat + HFD group. After 12 weeks of feeding, the serum biochemical indicators of the rats were measured. The liver and colon tissues were examined pathologically, and the microbial community diversity in the colon was analyzed. The results showed that brown rice significantly inhibited the increase of body weight and lowered serum total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) levels. Brown rice also significantly alleviated inflammatory cell infiltration in colon tissue (P < 0.05). Whole wheat reduced serum free fatty acid (FFA) levels and inhibited hepatic lipid accumulation in rats (P < 0.05). In the normal maintenance diet groups, brown rice decreased the Firmicutes/Bacteroidetes ratio and increased the relative abundance of Blautia and Lactobacillus in the colon, while whole wheat increased the relative abundance of Blautia and Romboutsia (P < 0.05). In the HFD groups, the relative abundance of harmful bacteria such as Terrisporobacter, Pseudomonas, Psychrobacter, and Lachnoclostridium were reduced by brown rice and whole wheat, while brown rice increased the relative abundance of Bacteroides in the colon (P < 0.05). Taken together, the intake of brown rice and whole wheat had a healthy effect on regulating intestinal homeostasis. The results of this study can provide a scientific basis for formulating reasonable whole-grain cereals-related dietary guidelines and developing whole-grain-based healthy products.

Keywords

• brown rice
• whole wheat
• whole grain
• obesity
• gut microbiota
• hypolipidemic effect