ObjectivesIn this study, the effects of γ-aminobutyric acid (GABA)-rich sprouted adzuki beans on the glycolipid metabolism and gastrointestinal health were investigated in mice with type 2 diabetes mellitus (T2DM).MethodsMice with T2DM were subjected to dietary intervention with different doses of GABA-rich sprouted adzuki beans for 6 consecutive weeks, during which growth indicators, glycolipid metabolism, and the composition and diversity of the gut microbiota changes were observed.ResultsA high dietary intake of GABA-rich sprouted adzuki beans had a preventive effect against weight gain, significantly reduced serum levels of FBG, TG, and TC. Additionally, high dietary intake of GABA-rich sprouted adzuki beans increased the abundances of Firmicutes, Bacteroidetes, Verrucomicrobia, and Akkermansia, leading to a shift in the structure of the gut microbiota toward the dominance of probiotics with regulatory effects on glycolipid metabolism.ConclusionsGABA-rich sprouted adzuki beans can effectively control the bodyweight of mice with T2DM, maintain a balanced blood glucose level, improve glycolipid metabolism and the changes in the microbiota may mediate the anti-diabetic effect of sprouted adzuki beans.

This study aimed to investigate the optimal hypoxic and monosodium glutamate (MSG) stress conditions for the enrichment of γ-Aminobutyric acid (GABA) in germinating adzuki beans and to reveal the potential underlying molecular mechanisms of GABA accumulation. Using single-factor experiments and response surface model, we investigated the effects of germination time, germination temperature, vacuum time, and MSG concentration on GABA contents, and further explored the activity and gene expression of glutamate decarboxylase (GAD) and polyamine oxidase (PAO) critical rate restriction enzymes during GABA synthesis. The optimal soaking temperature, soaking time, and pH conditions were 35°C, 16 h, and 5, respectively. Furthermore, the optimal germination conditions for optimal GABA enrichment were 48 h, 1.99 mg/ml MSG concentration, germination temperature of 31.49°C, and vacuum time of 15.83 h. Under such conditions, the predicted GABA concentration was 443.57 ± 7.18 mg/100 g, with no significant difference between the predicted and experimental data. The vacuum + MSG (FZM) treatment has a maximum contribution rate of GABA to 38.29%, which significantly increase GABA content, and the increase was associated with increased GAD and PAO activity. In addition, MSG in combination with vacuum treatment could significantly induce VaGAD4 and VaGAD6 genes in 2 days germination of adzuki beans. According to the results of the present study, vacuum + MSG treatment is an effective approach to enhancing GABA accumulation in germinating adzuki beans, which could be employed in enhancing the functional quality of germinating adzuki beans.

Type 2 diabetes mellitus (T2DM) is one of the most common metabolic diseases, and exploring strategies to prevent and treat diabetes has become extremely important. In recent decades the search for new therapeutic strategies for T2DM involving dietary interventions has attracted public attention. We established a diabetic mouse model by feeding mice a high-fat diet combined with injection of low-dose streptozotocin, intending to elucidate the effects and possible mechanisms of different dosages of γ-aminobutyric acid (GABA)-rich germinated adzuki beans on the treatment of diabetes in mice. The mice were treated for 6 weeks either with increasing doses of GABA-enriched germinated adzuki beans, with non-germinated adzuki beans, with GABA, or with the positive control drug metformin. Then, the blood glucose levels and blood lipid biochemical indicators of all the mice were measured. At the same time, serum differential metabolite interactions were explored by UPLC-Q/TOF-MS-based serum metabolomic analysis. The results showed that body weight and fasting blood glucose levels were significantly reduced (P < 0.05). We also report improved levels of total cholesterol, triglycerides, aspartate aminotransferase, alanine aminotransferase, urea, and serum creatinine. We observed a significant improvement in the homeostasis model assessment of the beta cell function and insulin resistance (HOMA-β and HOMA-IR) scores (P < 0.05) in the group of mice treated with the highest dose of GABA-enriched germinated adzuki beans. In addition, the metabolic profiles of the serum were analyzed, and 31 differential metabolites including amino acids and lipids were obtained. According to the Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis, this was found to be correlated with nine significantly enriched metabolic pathways involving the up-regulation of levels of L-serine, SM (d18:1/22:1(13Z)), L-histidine, creatine, and 3-indoleacetic acid. Our data suggest that the hypoglycemic effect of GABA-enriched germinated adzuki beans on diabetic mice may be related to improving tryptophan metabolism, glycerol phospholipid metabolism, sphingosline metabolism, and the glycine, serine, and threonine metabolic pathways. This study provides a reference for the application of GABA-enriched germinated foods in type 2 diabetes and could provide a cue for searching biomarkers to be adopted for T2DM diagnosis.

Studies have shown that inhibiting inflammation and regulating intestinal microflora imbalance is a significant factor in controlling the development of type 2 diabetes mellitus (T2DM). This experiment studied the protective effect of polyphenol extract from germinated mung beans on diabetic C57BL/6 mice.ResultsFasting blood glucose (FBG) was decreased, glucose tolerance was increased, insulin resistance was decreased, serum lipid indexes in T2DM mice were improved, and the enzyme activities of alanine aminotransferase (ALT) and aspartate transaminase (AST) in serum were reduced. Meanwhile, the levels of interleukin 6 (IL-6), tumor necrosis factor-α (TNF-α), and C-reactive protein (CRP) in serum were decreased, the concentration of interleukin 10 (IL-10) in serum was increased, inhibiting the inflammatory reaction induced by diabetes and repairing the morphology of mice liver tissue. At the same time, germinated mung bean polyphenol (GMP) can regulate the main intestinal flora, Firmicutes, Bacteroidetes, and Proteobacteria in diabetic mice and can also regulate species diversity and improve intestinal flora imbalance. Taken together, the experimental conclusion is a certain dose of polyphenol extract from germinated mung beans that can improve mouse T2DM by inhibiting inflammatory reaction and regulating intestinal microflora.

In order to improve the economic utilization of quinoa bran and develop a safe and highly available zinc ion biological supplement. In this study, a four-factor, three-level response surface optimization of quinoa bran soluble dietary fiber (SDF) complexation of zinc was studied. The effect used four factors on the chelation rate was investigated: (A) mass ratio of SDF to ZnSO4.7H2O, (B) chelation temperature, (C) chelation time, and (D) pH. Based on the results of the single-factor test, the four-factor three-level response surface method was used to optimize the reaction conditions. The optimal reaction conditions were observed as mentioned here: the mass ratio of quinoa bran SDF to ZnSO4.7H2O was 1, the reaction temperature was 65°C, the reaction time was 120 min, and the pH of the reaction system was 8.0. The average chelation rate was 25.18%, and zinc content is 465.2 μg/g under optimal conditions. The hydration method rendered a fluffy quinoa bran SDF structure. The intramolecular functional groups were less stable which made the formation of the lone pairs of electrons feasible to complex with the added divalent zinc ions to form a quinoa bran soluble dietary fiber-zinc complex [SDF-Zn(II)]. The SDF-Zn(II) chelate had higher 2,2-diphenylpicrylhydrazyl (DPPH), ABTS+, hydroxyl radical scavenging ability, and total antioxidant capacity. Therefore, metal ion chelation in dietary fiber is of biological importance.