The effects of quinoa bran dietary fiber on glucose and lipid metabolism and hepatic transcriptome in obese rats

Abstract BACKGROUND As a complex chronic metabolic disease, obesity not only affects the quality of human life but also increases the risk of various other diseases. Therefore, it is important to investigate the molecular mechanisms and therapeutic effects of dietary interventions that counteract obesity. RESULTS In this study, we extracted soluble (SDF) and insoluble dietary fiber (IDF) from quinoa bran using an enzymatic method and further investigated their effects on lipid metabolism and blood lipid levels in obese rats. Quinoa bran dietary fiber showed significantly reduced body weight, blood glucose level, total cholesterol, triglyceride, high‐density lipoprotein cholesterol, and low‐density lipoprotein cholesterol levels compared to those in the model group of obese rats. Aspartate aminotransferase and alanine aminotransferase levels were significantly lower in the IDF group, demonstrating that IDF improved liver injury more significantly than SDF, which was consistent with the analysis of liver tissue sections. IDF supplementation significantly improved the oxidation resistance of obese rats by decreasing malondialdehyde and increasing superoxide dismutase and glutathione peroxidase levels compared to the high‐fat diet group levels. Transcriptome analysis showed that IDF caused hepatic changes in genes ( Ehhadh , PPARα , FADS , CPT1 , CPT2 , SCD‐1 , Acadm , and CYP7A1 ) related to fatty acid degradation, and this result coincided with that of the gene expression validation result. CONCLUSION Overall, our research offers crucial data for the logical development of dietary fiber from quinoa bran with nutritional purposes. © 2023 Society of Chemical Industry.