苦荞对高脂膳食诱导小鼠生理及肠道菌群的影响

摘要

The objective of this work was to ascertain the effect of dietary supplementation of tartary buckwheat on the physiological metabolism and intestinal flora of dyslipidemic mice.For this purpose,a mouse model of dyslipidemia was created by feeding mice a high-fat diet (HFD).Changes in serum lipid metabolism-related indicators and the intestinal flora were determined respectively by high performance liquid chromatography and the plate count method and were correlated with each other.The results showed that HFD induced lipid metabolic disturbance and that both protein and starch from tartary buckwheat significantly reduced serum lipid levels in dyslipidemic mice to almost normal values (P ＜ 0.05).The number of beneficial intestinal bacteria (Bifidobacterium,Lactobacillus,and Enterococcus) in the tartary buckwheat starch and protein intervention groups was significantly higher than in the HFD group (P ＜ 0.05),and the number of harmful bacteria (Escherichia coli) was significantly lower (P ＜ 0.05).Furthermore,correlation analysis indicated that both tartary buckwheat starch and protein could adsorb bile acid and cholesterol and consequently promote their excretion,thereby regulating serum lipid metabolism and the intestinal microbial flora balance.Meanwhile,the increased proportion of intestinal priobiotic bacteria and the decreased proportion of harmful bacteria promoted lipid metabolism modulation and oxidative stress inhibition.Therefore,tartary buckwheat regulates blood lipid metabolism most likely by promoting bile acid salt excretion,regulating the intestinal flora balance,and improving oxidative stress.%以苦养为研究对象,通过高脂膳食诱导建立血脂代谢紊乱小鼠模型,利用高效液相色谱和平板计数对血脂代谢指标及肠道菌群的变化规律及其相关性进行研究,初步探究了苦荞对血脂代谢紊乱小鼠生理及肠道菌群的影响.结果表明:高脂膳食可引发小鼠血脂代谢紊乱,苦养淀粉和蛋白均能显著降低血脂指标(血清总胆固醇、甘油三酯、低密度胆固醇)的水平(P＜0.05),并基本恢复至空白组的水平.通过平板计数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)检测,发现苦荞淀粉和苦荞蛋白干预组的小鼠肠道菌中有益菌(双歧杆菌、乳酸菌、肠球菌)数量均显著高于高脂组(P＜0.05),有害菌(大肠杆菌)数量则显著低于高脂组(P＜0.05).此外,相关性分析结果表明,苦荞中蛋白和淀粉均可吸附胆汁酸与胆固醇并促进其排泄,从而不仅能调节血脂代谢又能调节肠道菌群平衡,同时,肠道菌群中益生菌比例的增多和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有着密切关系.