In an effort to evaluate the ameliorative effect of modified okara on obesity and hyperlipidemia, hyperlipidemic rats were orally administered with natural and modified okara and evaluated for body mass, blood lipids, visceral organ indexes and intestinal microbial abundance. The results showed that compared with the high-fat control group, the body mass, the serum levels of total cholesterol, triglyceride, low-density lipoprotein cholesterol (LDL-C) and liver index of rats administered with modified okara were decreased by 6.3%–13.3%, 19.7%–32.0%, 47.0%–59.3%, 43.2%–55.3%, and 5.4%–12.8%, respectively. Serum high density lipoprotein-cholesterol (HDL-C) concentration was increased by 20.9%–48.5%, and the structure of intestinal microbiota was different between the two groups. Okara proved helpful to improve obesity and hyperlipidemia in rats, and Na₂HPO₄ modified okara was more effective than raw and NaOH modified okara. The relative abundance of beneficial bacteria, such as Bacteroides, Lactobacillus and Lactobacillus murinus, was increased, and the relative abundance of harmful bacteria, such as Proteobacteria and Shigella, was decreased after administration of okara. Firmicute has no significant correlation with body mass or blood lipid indexes. The relative abundance of Lactobacillus was positively correlated with body mass and HDL-C concentration, and negatively correlated with TC, TG, and LDL-C concentrations. However, its effects on body mass and blood lipids were not synchronous. Bacteroidetes and Bacteroides were beneficial for blood lipid indexes. Proteobacteria and the genus Escherichia Shigella in this family have negative effects on blood lipids. In summary, modified okara improves obesity and hyperlipidemia in rats by regulating the intestinal flora.

This study intended to investigate the efficacy of dietary fiber in preventing obesity and regulating the intestinal microflora. C57BL/6 mice were fed D12492 high-fat diet supplemented with pomelo peel, insoluble dietary fiber (IDF) from pomelo peel or soluble dietary fiber (SDF) from pomelo peel. Those fed a maintenance diet or the high-fat diet served as normal control and obesity control groups, respectively. The feeding period lasted for 67 days. The changes in food intake, body mass, blood biochemical indexes, visceral indexes and intestinal microflora of the mice were observed during the feeding period. The results showed that compared with the obesity control group, body mass, serum total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) levels, epididymal fat coefficient and Lee’s index decreased by 4.9%, 8.3%, 14.29%, 0.44% and 2.54% in the IDF group, decreased by 5.1%, 11.4%, 21.21%, 0.60% and 2.47% in the SDF group, but increased by 1.3%, 7.4%, 12.5%, 0.96% and 1.27% in the pomelo peel group, respectively. The concentration of HDL-C increased by 0.52%, 0.78% and 5.44% in the IDF, SDF and pomelo peel groups, respectively. Moreover, dietary fiber from pomelo peel increased the relative abundance of Bacteroidetes and Lachnospiraceae_NK4A136_group, and decreased the relative abundance of Firmicutes, Desulfobacterota and Deferribacterota. Therefore, both SDF and IDF from pomelo peel have a significant effect on preventing obesity and lowering blood lipids, probably not by inhibiting food intake but rather by increasing the relative abundance of Bacteroidetes and Lachnospiraceae_NK4A136_group, and decreasing the relative abundance of Desulfobacterota and Deferribacteres. The increase in the relative abundance of Firmicutes is not significantly correlated with body mass, but significantly positively correlated with HDL-C and negatively correlated with LDL-C, which is beneficial to lipid control. The increase in the relative abundance of Bacteroidetes is significantly negatively correlated with body mass, TC and HDL-C levels, and significantly positively correlated with LDL-C levels, which is conducive to body mass control, but not blood lipid control. Hence, the effects of Bacteroidetes and Firmicutes on body mass and blood lipids need to be further studied. Pomelo peel dietary fiber can increase body mass and LDL-C levels by increasing food intake, but also significantly increase HDL-C levels. Similarly, its benefits in controlling body mass and blood lipids need to be further confirmed.