【作者】 庞博；

【导师】 单毓娟；

【作者基本信息】 哈尔滨工业大学 ， 化学工程（专业学位）， 2019， 硕士

【摘要】 随着饮食文化的西方化,我国居民全谷物摄入严重不足。大量流行病学研究表明,摄入充足的全谷物食品有助于预防和缓解多种慢性疾病如糖尿病、心血管疾病等的发生发展。本课题组前期采用一种全谷物食品-发芽糙米(germinated brown rice,GBR)对II型糖尿病(type 2 diabetes mellitus,T2DM)患者进行3个月的干预试验,结果表明患者的血糖、胰岛素水平均有较为明显的改善作用。鉴于II型糖尿病发病逐年上升,且与糖代谢、脂肪酸代谢、氨基酸代谢以及能量代谢等呈现复杂的交互作用,本研究从支链氨基酸(branched chain amino acids,BCAAs)和短链脂肪酸(short-chain fatty acids,SCFAs)代谢两方面探讨GBR改善II型糖尿病患者血糖和胰岛素抵抗的机制。本课题主要内容与结果如下:患者身体指标与一般情况比较:年纪在60-70岁的糖尿病人群中,吸烟饮酒情况占大多数,运动时间较短、强度较低,部分伴有高血压及高血脂,同时都患有不同程度的肥胖;试验组和对照组干预前的身高、体重、身体质量指数(body mass index,BMI)和营养素摄入等都没有显著差别(P>0.05)。而经GBR干预后,膳食纤维有显著升高(P<0.05)。发芽糙米能改善血糖及胰岛素水平:GBR干预后的空腹血糖显著下降(P<0.05),胰岛素分泌水平也得到显著改善(P<0.05),胰岛功能指数(HOMA-IR、HOMA-β及Matsuda index)有显著恢复(P<0.05)。发芽糙米能显著降低血清支链氨基酸的浓度:经发芽糙米干预后,利用LC-MS/MS测定的血清中BCAAs(Val、Leu和Ile)含量显著下降(P<0.05)。二分类Logistic回归分析结果显示,血糖和能量为BCAAs的危险因素(OR>1);胰岛素为保护因素(OR<1)。发芽糙米能促进BCAAs和葡萄糖分解代谢:BCAAs分解关键酶BCATm和BCKDH的mRNA表达水平显著升高(P<0.05)。患者血清中丙酮酸脱氢酶(pyruvate dehydrogenase,PDH)活性下降而乳酸脱氢酶(lactate dehydrogenase,LDH)活性升高(P<0.05)。发芽糙米促进产SCFAs肠道菌群的形成:粪便中SCFAs(乙酸、丙酸、丁酸)含量显著增加(P<0.05)。肠道菌群和SCFAs相关性分析发现,粪杆菌和拟杆菌与短链脂肪酸浓度呈显著正相关(P<0.05)。多元回归分析结果显示,丁酸和胰高血糖素样肽-1为糖尿病的保护因素。综上,发芽糙米能够改善II型糖尿病受试者的相关生化指标,其作用机制与改善胰岛素抵抗、支链氨基酸代谢以及短链脂肪酸代谢有关。本研究将为我国居民更好的了解全谷物发芽糙米的营养和健康作用,并且了解膳食调整支链氨基酸和膳食纤维的结构来树立新的健康观念。更多还原

【Abstract】 With the westernization of the dietary culture of our residents,the whole grain intake was seriously insufficient.A large number of epidemiological studies had shown that adequate intake of whole grain foods can help prevent and alleviate the development of many chronic diseases such as diabetes and cardiovascular diseases.In the early stage,our group used a whole-grain food-germinated brown rice(GBR)to conduct a three-month intervention test on patients with type 2 diabetes mellitus(T2DM).The results showed that there was an obvious improvement between the patient’s blood glucose and insulin levels.Given the increasing incidence of type 2diabetes and complex interactions with the metabolism of glucose,fatty acid,amino acid,and energy,this study had derived from branched chain amino acids(BCAAs)and short-chain fatty acids(short-chain)to explore the mechanism of GBR in improving blood glucose and insulin resistance in type 2 diabetic patients.The main contents and results of this topic are as follows:The patient’s physical indicators and the general situation comparison: In the 60-70 years old diabetes,the number of people who smoked and drank alcohols population accounted for the majority of the total.The patient’s condition was shorter exercise time,lower intensity,some with hypertension and hyperlipidemia,and all had different degrees of obesity.There were no significant differences in height,weight,body mass index(BMI)between the intervention group and the control(P>0.05).Analysis of the results of dietary questionnaire showed that there a significant difference in dietary fiber(P<0.05).GBR can improve blood glucose and insulin levels: Fasting blood glucose and islet function index after GBR intervention decreased significantly(P<0.05).The results’ analysing of dietary questionnaire showed that there was no significant difference in energy and protein intake(P>0.05),while there was a significant difference in dietary fiber(P<0.05).GBR rice can significantly reduce the concentration of BCAAs in serum:The concentration of BCAAs(Val,Leu and Ile)in serum was significantly decreased by LC-MS/MS after GBR intervention(P<0.05).The results of logistic regression analysis showed that blood glucose and energy were risk factors for BCAAs(OR>1);insulin was a protective factor(OR<1).GBR can promote BCAAs and glucose catabolism: the mRNA expression levels of BCATm and BCKDH(the key enzymes of BCAAs decomposition)were significantlyincreased(P<0.05).Serum pyruvate dehydrogenase(PDH)activity decreased and lactate dehydrogenase(PDH)activity increased(P<0.05).Germinated brown rice promoted the formation of intestinal flora in SCFAs;the content of short-chain fatty acids(acetic acid,propionic acid,butyric acid)in feces increased significantly(P<0.05).Correlation analysis between intestinal flora and SCFAs showed that there was a significant positive correlation between the concentrations of Faecalibacterium,Bacteroides,and short-chain fatty acids(P<0.05).Multiple regression analysis showed that butyric acid and glucagon-like peptide-1 were protective factors for diabetes.In summary,GBR can improve the biochemical indicators of type II diabetes,and its mechanism is related to the improvement of insulin resistance,the metabolism of BCAAs and SCFAs.This study will provide a better understanding of the nutritional and health effects of whole grain GBR for our residents,and understand the structure of dietaryly adjusted branched chain amino acids and dietary fiber to establish a new concept of health.更多还原