高直链玉米淀粉对大鼠肠道发酵影响的研究

目的:研究高直链玉米淀粉(high amylase corn starch,HACS)对大鼠肠道发酵的影响。方法:将30只Wistar成年雌鼠随机分为5组,分别喂不添加(对照)和添加5%、10%、20%、30%HACS的饲料。喂养4w后,解剖取小肠、盲肠及盲肠内容物,测定各组体重、饲料效率及淀粉消化率、小肠内容物、盲肠内容物、盲肠组织重量、表面积及盲肠中短链脂肪酸(SCFA)和pH值等。结果:随着饲料中HACS添加量的增加,淀粉表观消化率显著降低,肠道未消化物重量及粪重显著增加。添加20%和30%HACS组的盲肠中乙酸、丙酸、丁酸、丁二酸和总SCFA及盲肠组织重量均显著高于对照组,但30%HACS组的丙酸、丁酸和总SCFA均低于20%HACS组。添加HACS各组盲肠的pH值均低于对照组,其中20%和30%HACS组达显著水平(P<0.05)。结论:饲料中添加HACS能明显提高盲肠中SCFA的产量,且有明显的剂量关系。

EFFECT OF HIGH AMYLOSE CORN STARCH ON INTESTINAL FERMENTATION IN RATS

Objective: To study the effects of high amylose corn starch (HACS) on intestinal fermentation in rats. Method: Thirty mature female Wistar rats were divided into 5 groups, and fed on control diet (no HACS) and diets containing 5%, 10%, 20%, 30% HACS respectively for 4 w. Small intestinal and cecal tissue and contents were collected, and body weight gain, feed efficiency, starch digestibility, cecal area and weight, amount of short chain fatty acids(SCFA)and pH in cecal contents were determined. Results: The starch apparent digestibility was decreased, and the dry weights of indigested food in intestine and feces were increased with increase of HACS dose in diets. The amounts of acetic, propionic, butyric, succinic acid and total SCFA in cecal contents, and cecal tissue weight in 20%HACS and 30%HACS groups were significantly higher than those in control group (P < 0.05), while pH in cecum was significantly lower than in control group (P < 0.05). Conclusion: HACS may significantly increase the amounts of SCFA in cecum at dose-dependent relationship.