Purpose: Obesity, a strong risk factor for metabolic disorder, has become a major impediment for public health globally. The objective of this study was to assess the anti-obesity effect of mung bean, and the relationship between the gut microbiota modulatory effects of mung bean and the prevention of obesity.
Methods: Thirty-two four-week-old male C57BL/6 J mice were divided into four groups: normal chow diet (NCD), high-fat diet (HFD), a high-fat diet supplemented with 30% whole mung bean flour (HFD-WMB), and a high-fat diet supplemented with 30% decorticated mung bean flour (HFD-DMB). The ability of a mung bean-based diet to combat obesity-related metabolic disorder was determined by assessing the changes in physiological, histological, biochemical parameters, and gut microbiota composition of mice with HFD-induced obesity at 12 weeks.
Results: Both of WMB and DMB supplementation can effectively alleviate HFD-induced lipid metabolic disorders, which was accompanied by a reduction in hepatic steatosis. However, the only supplementation with WMB significantly reduced HFD-induced body weight gain, fat accumulation, and adipocyte size, and ameliorated the glucose tolerance and insulin resistance by sensitizing insulin action. Furthermore, high-throughput pyrosequencing of 16S rRNA revealed that WMB and DMB supplementation could normalize HFD-induced gut microbiota dysbiosis. Especially, WMB and DMB supplementation significantly promoted the relative abundance of Akkermansia and Bifidobacterium, respectively, and both of them significantly restored the relative abundance of several HFD-dependent taxa back to normal status in this study. Spearman's correlation analysis revealed that those genera are closely correlated with obesity-related indices.
Conclusions: Although WMB showed better beneficial effects on HFD-induced obesity in comparison with DMB, DMB still retained some health benefits. Moreover, the alleviation of HFD-induced changes by mung bean supplementation was, at least, partially conciliated by structural modulation of gut microbiota.
Keywords: Decorticated mung bean; Gut microbiota; Lipid disorders; Obesity; Whole mung bean.