苦荞蛋白对小鼠血脂代谢紊乱与肠道菌群调节作用的研究

发布时间：2018-01-02 08:37

  本文关键词：苦荞蛋白对小鼠血脂代谢紊乱与肠道菌群调节作用的研究　出处：《上海应用技术大学》2016年硕士论文　论文类型：学位论文

  更多相关文章： 苦荞蛋白 血脂代谢 抗氧化 肠道菌群

【摘要】：随着人民生活水平的提高,膳食结构发生了巨大的变化,膳食中油脂的比例不断增多,可诱发血脂代谢紊乱与氧化应激,影响肠道菌群平衡,危害人体健康。苦荞富含多种功能因子,如：苦荞蛋白,黄酮类化合物,抗性淀粉等,其中苦荞蛋白是一种难消化的蛋白,具有吸附胆酸盐活性调节脂代谢的作用,但目前鲜有研究涉及苦荞蛋白对肠道菌群影响及其与调节血脂代谢的关联。因此,本文通过膳食诱发血脂代谢紊乱小鼠模型探究苦荞蛋白对干预高脂代谢紊乱、氧化应激与肠道菌群失衡作用之间的关联。C57BL/6雄性小鼠随机分为5组(每组9只)：空白组(Blank,AIN-93G饲料)；高脂组(HFD,10%脂肪,1%胆固醇,0.5%胆酸钠)；苦荞粉干预组(PBF,高蛋白含量苦荞粉)；苦荞蛋白干预组(BWP)；黄酮干预组(Fla,0.5%苦荞黄酮提取物)。饲喂6w后,分析血浆与组织匀浆液的血脂血糖代谢相关生化指标、抗氧化活性指标,并通过LC-MS、GC-MS和分子生物学技术分析肠道主要菌群及其代谢产物的变化。研究结果如下：(1)高脂膳食可引发小鼠血脂代谢紊乱、胰岛素敏感性(ISI)显著下降(P0.05)、氧化应激,PBF和BWP能显著降低血脂指标(TC、TG、LDL-C)、血糖指标(GLU、INS)、动脉硬化指数(AI)和脂质过氧化物指标(MDA)的含量,提高HDL-C含量、ISI和组织的抗氧化活性(T-AOC、SOD、CAT),并基本恢复至空白组的水平。(2)PBF组蛋白质和粗脂肪的表观消化率较HFD组分别显著降低了9.76%和4.06%,BWP组的分别显著降低了6.93%和2.05%。PBF组和BWP组小鼠粪便中总胆汁酸和胆固醇的排泄较HFD组显著增加,且肠道内容物中乙酸、丙酸、丁酸含量显著升高。相关性分析表明：总胆汁酸和胆固醇的排泄量与HDL-C和ISI呈显著正相关。表明苦荞蛋白质难消化,未消化的蛋白质可吸附胆酸与固醇排除体外,可能从而干预了血脂代谢紊乱。(3)通过平板计数以及PCR技术对各组小鼠的肠道主要菌群(双歧杆菌、乳酸菌、大肠杆菌、肠球菌)进行检测,二者结果的变化趋势基本一致,即PBF组与BWP组的有益菌(双歧杆菌、乳酸菌、肠球菌)数量均显著高于HFD组,有害菌(大肠杆菌)数量则显著低于HFD组。相关性分析表明：肠道中双歧杆菌数量与血脂指标(TC、TG、LDL-C)呈显著负相关,大肠杆菌数量与肠道的MDA呈显著正相关。表明苦荞蛋白具有调节高脂膳食小鼠肠道菌群失衡的作用,可能从而一定程度抑制血脂的紊乱及组织的氧化应激。综上所述,较难消化的苦荞蛋白可吸附胆酸与胆固醇促进其排泄,从而即调节血脂代谢又调节肠道菌群平衡,而肠道菌群中益生菌比例增多有害菌比例的降低又对血脂代谢调节与抑制氧化应激有着一定促进作用。因此,苦荞蛋白对血脂代谢调节作用可能与其促进胆酸排泄、调节肠道菌群平衡、改善氧化应激等方面作用途径有着密切关系。
[Abstract]:With the improvement of people's living standard, the dietary structure has changed greatly, and the proportion of fat in diet is increasing, which can induce lipid metabolism disorder and oxidative stress, and affect the balance of intestinal flora. Tartary buckwheat is rich in many functional factors, such as Tartary buckwheat protein, flavonoids, resistant starch and so on, among which Tartary buckwheat protein is an indigestible protein. It has the function of adsorbing cholate activity to regulate lipid metabolism, but there are few studies on the effect of Tartary buckwheat protein on intestinal flora and its relationship with the regulation of lipid metabolism. In this paper, the effect of Tartary buckwheat protein (Tartary buckwheat protein) on hyperlipidemia was investigated in mice model of hyperlipidemia induced by diet. The relationship between oxidative stress and intestinal flora imbalance. C57BL / 6 male mice were randomly divided into 5 groups (9 rats in each group): blank group (Blanck AIN-93G feed); In the hyperlipidemia group, 10% HFDF 10% fat and 1% cholesterol 0. 5% sodium cholate; Tartary buckwheat powder intervention group, high protein content of Tartary buckwheat powder; Tartary buckwheat protein intervention group (BWPN); The flavonoid intervention group was fed with 0.5% Tartary buckwheat flavone extract for 6 weeks. The biochemical indexes of blood lipids metabolism and antioxidant activity of plasma and tissue homogenate were analyzed by LC-MS. GC-MS and molecular biology techniques were used to analyze the changes of intestinal microflora and its metabolites. The results were as follows: 1) High fat diet could induce lipid metabolism disorder in mice. Insulin sensitivity index (ISI) decreased significantly (P 0.05), and oxidative stress and BWP significantly decreased serum lipids, TGG, LDL-C and GLU. The contents of HDL-C and T-AOC SOD in tissues were increased by the contents of HDL-C and lipid peroxides (MDA), the arteriosclerotic index (AII) and the antioxidant activity (T-AOC) of the tissue. The apparent digestibility of protein and crude fat in HFD group was significantly lower than that in HFD group by 9.76% and 4.06% respectively. The excretion of total bile acid and cholesterol in BWP group was significantly lower than that in HFD group. The excretion of total bile acid and cholesterol in the feces of PBF group and BWP group were significantly higher than that in HFD group, and acetic acid in intestinal contents. The content of propionic acid and butyric acid was significantly increased. Correlation analysis showed that the excretion of total bile acid and cholesterol was positively correlated with HDL-C and ISI, indicating that Tartary buckwheat protein was indigestible. The undigested protein can adsorb cholic acid and steroid to exclude in vitro, which may interfere with dyslipidemia. The main intestinal flora (Bifidobacterium) of mice in each group was determined by plate counting and PCR technique. Lactic acid bacteria, Escherichia coli, enterococcus were detected, the results of the two changes are basically the same trend, that is, PBF group and BWP group of beneficial bacteria (Bifidobacterium, lactic acid bacteria). The number of Enterococcus was significantly higher than that of HFD group, and the number of harmful bacteria (Escherichia coli) was significantly lower than that of HFD group. LDL-C was negatively correlated, and the number of Escherichia coli was positively correlated with intestinal MDA, indicating that Tartary buckwheat protein could regulate intestinal microflora imbalance in high-fat diet mice. In conclusion, the more difficult to digest Tartary buckwheat protein can adsorb cholic acid and cholesterol to promote its excretion. Thus regulating the metabolism of blood lipids and regulating the balance of intestinal flora, and the increase of the proportion of probiotics in the intestinal bacteria proportion of harmful bacteria in the proportion of lipid metabolism regulation and inhibition of oxidative stress has a certain role in promoting. The effects of Tartary buckwheat protein on lipid metabolism may be closely related to the regulation of cholic acid excretion, the regulation of intestinal microflora balance and the improvement of oxidative stress.
【学位授予单位】：上海应用技术大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：R151
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本文编号：1368487