抗性淀粉对大鼠肠道菌群的影响

目的观察抗性淀粉(RS)及其不同类型的摄入对大鼠肠道常见菌群的影响。方法将32只大鼠按体重随机分为4组,每组8只,分别喂以不含RS的饲料、含6%二型抗性淀粉(RS2)、含12%RS2和含6%三型抗性淀粉(RS3)饲料4周。收集大鼠实验前后的粪便,检测其pH值和5种常见菌群(大肠杆菌、拟杆菌、肠球菌、双歧杆菌、乳杆菌)的分布。饲养4周后,处死大鼠取其盲肠内容物,检测其pH值和短链脂肪酸(SCFA)的含量。结果RS2和RS3均可明显增加大鼠粪便中双歧杆菌菌落数(P<005),显著减少肠球菌落数(P<005);盲肠内容物的SCFA随RS2摄入增加而增加,12%RS2组显著高于对照组(P<001),也高于6%RS2组(P<005);RS可降低大鼠盲肠内容物和粪便的pH值(P<005),降低效果随RS摄入量增加而加大,且RS3组优于RS2组(P<005)。结论抗性淀粉可明显改善机体的肠道菌群,并增加其酵解产物SCFA,降低肠道pH值,从而发挥对机体的健康作用。

Influence of resistant starch on colon flora of mice

Objective To investigate the effect of resistant starch (RS_2 and RS_3) intake on colon flora of mice.Methods 32 mice were divided into four groups (8 mice/group) according to their weight randomly.Four groups of mice were given basic feed (containing only corn starch and no RS),containing 6% RS_2 feed,containing 12% RS_2 feed,and containing 6% RS_3 feed,respectively.Feces were collected on the 1st and 29th day of the experiment,and pH of feces were measured and five feces flora (enterobacter,bifidobacteria,lactobacillus,bacteroid,and enterococcus) were detected with culture medium method.All the mice were killed on the 29th day to get caecum content.The pH of caecum content were measured and short chain fatty acid (SCFA) were detected with gas chromatography.Results RS_2 and RS_3 could all increase feces bifidobacteria (P<0.05) and decrease enterobacteria (P<0.05).RS_2 could increase SCFA of ceacum content,and 12% RS_2 group is more than control group(P<0.01),and also more than 6% RS_2 group (P<0.05).RS could also decrease pH of feces and ceacum content of mice,and the effect of RS_3 is more than RS_2. Conclusion Resistant starch could improve colon flora,increase its fermentable production SCFA,decrease caecum and feces pH,and then improve health.