苦荞中可溶性及不可溶性膳食纤维调控糖尿病小鼠糖脂代谢的功效

Regulatory Effect of Soluble and Insoluble Dietary Fiber from Tartary Buckwheat on Glucose and Lipid Metabolism in Diabetic Mice

本研究采用苦荞麸皮粉中提取的膳食纤维对高脂/链脲佐菌素诱导的糖尿病小鼠进行干预,比较苦荞麸皮粉中的可溶性膳食纤维(soluble dietary fiber,SDF)和不可溶性膳食纤维(insoluble dietary fiber,IDF)的含量及作用差异,解析苦荞中SDF及IDF对调控糖尿病小鼠血糖及血脂代谢作用的贡献。结果:苦荞麸皮中IDF的质量分数((19.52±0.21)%)约为SDF((4.02±0.19)%)的5倍;相同干预剂量下SDF比IDF能更有效地发挥降血糖作用,但当IDF干预剂量达到SDF的5倍时,IDF降低血清中的总胆固醇和低密度脂蛋白胆固醇水平的效果更显著(P<0.05),并且能够和SDF一样有效促进胰岛素分泌并改善糖耐量、降低肝脏中总胆固醇水平、促进短链脂肪酸的产生。结论:苦荞SDF和IDF均具有改善糖耐量、降低血清及肝脏中脂肪积累的功效,且都与盲肠中短链脂肪酸含量的增加密切相关;研究揭示了苦荞SDF及IDF在量效关系上的差异,为充分理解谷物中不同膳食纤维的糖脂调控功效提供了科学证据。

The present study examined the contents and glucose lowering capacities of soluble dietary fiber(SDF)and insoluble dietary fiber(IDF)from tartary buckwheat bran,and it comparatively evaluated the effect of supplementation with the two types of dietary fiber on glucose and lipid metabolism in high-fat diet/streptozotocin-induced diabetic mice.The content of IDF in tartary buckwheat bran was(19.52±0.21)%,approximately 5 times as high as that of SDF((4.02±0.19)%).SDF was more effective than IDF in lowering blood glucose at the same dose.However,when administered at a dose five times higher than SDF dose,IDF was more effective in lowering serum total cholesterol(TC)and low density lipoprotein cholesterol(LDL-C)than SDF;and promoted insulin secretion,improved glucose tolerance,lowered hepatic total cholesterol(TC)and stimulated the production of short-chain fatty acids(SCFAs)as effectively as did SDF.Therefore,both SDF and IDF could improve glucose tolerance and lower lipid accumulation in serum and liver,which were closely associated with the increase in the production of SCFAs in the cecum content.The results from this study may provide a scientific basis for understanding the regulatory effect of different types of dietary fiber from cereals on glucose and lipid metabolism.