抗性淀粉对饮食诱导肥胖大鼠肠道发酵状况的改善作用

Improvement of resistant starch on intestinal fermentation in diet-induced obese rats

目的:探讨抗性淀粉(RS)对饮食诱导肥胖(DIO)大鼠肠道发酵状况的影响,阐明RS改善肠道功能的可能机制。方法:选择SD大鼠60只,随机分为对照组和高脂组,基础饲料适应1周后,分别用普通饲料和高脂饲料喂养7周,根据体质量筛选出DIO大鼠。将DIO大鼠随机分成肥胖对照组和不同剂量RS组,共5组。肥胖对照组用高脂饲料继续喂养,另4个实验组分别用含5%、10%[同时用5%的硫酸葡聚糖(DS)1mL灌胃,即10%RS+DS组]、10%及15%RS的高脂饲料喂养,5周后测定各组大鼠体质量、脂体比、盲肠面积、肓肠内容物质量及其pH值、短链脂肪酸(乙酸、丙酸、丁酸)的变化情况。结果:与对照组比较,10%RS组和15%RS组大鼠体质量、脂体比和盲肠内容物pH值下降(P<0.05);15%RS组大鼠盲肠面积增加(P<0.05);5%、10%及15%RS组大鼠盲肠内容物乙酸、丙酸及丁酸含量升高(P<0.01);10%RS组和10%RS+DS组大鼠盲肠内容物质量下降(P<0.05);10%RS+DS组大鼠盲肠内容物乙酸、丙酸含量升高(P<0.01)。RS添加量与大鼠体质量呈负相关关系(r=0.862,P<0.01),与肓肠内容物乙酸、丙酸、丁酸含量呈正相关关系(r1=0.945,r2=0.943,r3=0.949,P<0.01)。结论:RS可增加饮食诱导肥胖大鼠盲肠面积,降低盲肠内容物pH值,提高粪便中短链脂肪酸水平,可以改善DIO大鼠肠道发酵功能。

Objective To study the effects of resistant starch （RS） on intestinal fermentation in diet-induced obese （DIO） rats, and to clarify the possible mechanism of RS to improve intestinal function. Methods 60 SD rats were divided randomly into 2 groups. One of the groups was selected as control group, and the rats were fed with normal foods. The rats in the other group were fed with high-fat foods for 7 weeks. The DIO rats were divided into five groups, and were fed, for 5 weeks, respectively with high-fat foods, hight-fat foods containing 50% RS, 10% RS, 15% RS, and 10% RS plus dextran sulfate （DS） as inhibitor to butyric acid. Then, small intestinal and cecal tissue and cecal contents were collected, and body weight gain, the ratio of fat to body, cecal area and weight, amount of short chain fatty acids （SCFA） and pH in cecal contents were determined. Results Compared with control group, the body weights, ratio of fat to body and pH of cecal contents of the rats in 10%RS group and 15% RS group were decreased （P〈0.05）. the cecal area in 15%RS group was increased （P〈0.05）. The acetic acid, propionic acid and butyric acid levels in faeces in 5%, 10% and 15%RS groups were increased （P〈0.01）. The weights of cecal contents in 10%RS group and 10%RS＋DS group were decreased （P〈0.05）. The acetic acid and propionic acid levels in faeces in 10%RS＋DS group were increased （P〈0.01）. The dose of RS was negatively related to the rat body weight （r=-0. 862, P〈0.01） and was positively related to the levels of acetic acid, propionic acid and butyric acid in cecal contents of rats （r1 =0. 945, r2 =0. 943, r3 =0. 949, all P〈0.01）. Conclusion RS may significantly increase the cecal area, reduce the pH of cecal contents and increase short chain fatty acid levels in faeces. It is certified that RS can improve intestinal fermentation function of DIO rats.