In this study, the level of gamma-aminobutyric acid (GABA) in wheat bran was increased to be six times higher through the action of endogenous glutamate decarboxylase compared with untreated bran. The process of GABA formation in wheat bran also led to an increased level of phenolic compounds with enhanced antioxidant capacity 2 times higher than the untreated status. The interventional effect of a diet containing GABA-enriched bran on hyperinsulinemia induced by a high-fat diet (HFD) was investigated in a rat model. The results showed that, when compared with animals fed with HFD-containing untreated bran (NB group), the consumption of HFD-containing GABA-enriched bran (GB group) demonstrated a greater improvement of insulin resistance/sensitivity as revealed by the changes in the homeostatic model assessment for insulin resistance index (HOMA-IR) and the quantitative insulin sensitivity check index (QUICKI). The expression of hepatic genes, cytochrome P450 family 7 subfamily A member 1 (Cyp7a1) and ubiquitin C (Ubc), which are involved in the adipogenesis-associated PPAR signalling pathway, was found to be significantly down-regulated in the GB group compared with the HFD group (P = 0.0055). Meanwhile, changes in the expression of a number of genes associated with lipid metabolism and gluconeogenesis were also noted in the GB group versus the HFD group, but not in the NB group, indicating different regulatory patterns between the two brans in a high-fat diet. More importantly, the analysis of key genes related to glucose metabolism further revealed that the expression of insulin-induced gene 1/2 (Insig-1/2) was increased following GB intervention with a corresponding reduction in phosphoenolpyruvate carboxykinase 1 (Pepck) and glucose-6-phosphatase, catalytic subunit (G6pc) expression, suggesting that glucose homeostasis is greatly improved through the intervention of GABA-enriched bran in the context of a high-fat diet.

中文翻译：

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富含丰富的γ-氨基丁酸的麦麸可减轻高脂饮食引起的葡萄糖耐受不良和高胰岛素血症。

在这项研究中，与未经处理的麸皮相比，通过内源性谷氨酸脱羧酶的作用，麦麸中的γ-氨基丁酸（GABA）水平提高了六倍。麦麸中GABA的形成过程还导致酚类化合物含量增加，其抗氧化能力增强，为未处理状态的2倍。在大鼠模型中，研究了含有富含GABA的麸皮的饮食对高脂饮食（HFD）诱导的高胰岛素血症的干预作用。结果表明，与饲喂含有HFD的未经处理的麸皮的动物（NB组）相比，食用富含HFD的富含GABA的麸皮（GB组）证明了胰岛素抵抗/敏感性的改善更大，这可以通过对胰岛素抵抗指数（HOMA-IR）和定量胰岛素敏感性检查指数的稳态模型评估的变化来揭示（ QUICKI）。发现与脂肪形成相关的PPAR信号通路有关的肝基因，细胞色素P450家族7亚家族A成员1（Cyp7a1）和泛素C（Ubc）的表达与GB组相比明显下调。 HFD组（P = 0.0055）。同时，与高脂饮食组相比，GB组和HFD组中也注意到与脂质代谢和糖异生相关的许多基因表达的变化，而NB组则没有，这表明高脂饮食中两个麸皮之间的调节方式不同。 。