干酪乳杆菌对不同剂量丙烯酰胺诱导大鼠肠道损伤的保护效果

目的:研究干酪乳杆菌对不同剂量丙烯酰胺诱导大鼠肠道损伤的保护效果。方法:105只雄性W i s t a r大鼠,随机分为7组。正常对照组给予生理盐水灌胃;低、中、高剂量丙烯酰胺组分别给予5、1 5、30 mg/(kg·d mb)丙烯酰胺灌胃;干酪乳杆菌干预低、中、高剂量丙烯酰胺组给予2.1×109 CFU/(kg·d mb)干酪乳杆菌饮品灌胃,同时分别给予5、15、30 mg/(kg·d mb)丙烯酰胺灌胃。实验周期为4周。末次灌胃后收集各组大鼠粪便,禁食12 h后麻醉,腹主动脉取血,留取小肠组织。透射电子显微镜观察大鼠小肠组织超微结构的改变;采用酶联免疫吸附测定法检测大鼠血浆中D-乳酸(D-lactic acid,D-LA)和二胺氧化酶(diamine oxidase,DAO)的浓度变化;实时荧光定量聚合酶链式反应检测干酪乳杆菌对大鼠肠道菌群的影响。结果:与正常对照组相比,中、高剂量丙烯酰胺组小肠紧密连接肿胀,微绒毛排列稀疏,微绒毛长度明显缩短(P0.05);干酪乳杆菌干预后,大鼠小肠微绒毛排列情况均得到不同程度的改善。与正常对照组相比,中、高剂量丙烯酰胺组大鼠血浆中D-LA和DAO水平明显升高(P0.05);干酪乳杆菌干预后,大鼠血浆中D-LA和DAO水平显著降低(P0.05)。与正常对照组相比,中、高剂量丙烯酰胺组大鼠粪便中大肠杆菌和粪肠球菌的数量明显升高(P0.05),双歧杆菌和乳杆菌的数量明显降低(P0.05);干酪乳杆菌干预后,大鼠粪便中大肠杆菌和粪肠球菌的数量均有不同程度的减少,双歧杆菌和乳杆菌的数量均有不同程度的增加。结论:干酪乳杆菌对不同剂量丙烯酰胺诱导大鼠的肠道损伤具有一定程度的保护效果,其机制可能与改善肠黏膜屏障功能、调节肠道菌群有关。

Protective Effect of Lactobacillus casei on Acrylamide-Induced Intestinal Injury in Rats

Objective: To investigate the protective effect of Lactobacillus casei on acrylamide-induced intestinal injury in rats. Methods: Male Wistar rats were randomly divided into following seven groups: control group (normal saline), low-, medium-, and high-dose acrylamide (5, 15, and 30 mg/(kg·d mb)) groups, and Lactobacillus casei 2.1 × 109 CFU/(kg·d mb)] plus low-, medium-, and high-dose acrylamide (5, 15, and 30 mg/(kg·d mb )) groups. The experimental period was 4 weeks. Feces were collected after the last treatment. Twelve hours after fasting, the rats were anesthetized to collect blood samples. The small intestine was obtained for the observation of ultrastructural changes by transmission electron microscope (TEM). Plasma D-lactic acid (D-LA) and diamine oxidase (DAO) concentration were measured by enzymelinked immunosorbent assay. The intestinal microbiota was detected by real-time PCR. Results: The ultrastructural changes observed by TEM showed that the tight junction was swelled; the microvilli, with significantly shortened length (P < 0.05), were loosely arranged in the medium-, and high-dose acrylamide groups. However, the control group did not show abnormal ultrastructure. Abnormal ultrastructural changes were rescued by Lactobacillus casei treatment. The plasma concentration of D-LA and DAO in the medium-, and high-dose acrylamide (15 and 30 mg/kg) groups were significantly elevated (P < 0.05) when compared with the control group. But in the Lactobacillus casei treatment groups, the plasma concentrations of D-LA and DAO were significantly reduced (P < 0.05) when compared with the medium-, and high-dose acrylamide (15 and 30 mg/kg) groups. Compared with the control group, Escherichia coli and Enterococcus faecalis were significantly increased (P < 0.05), and Bifidobacterium and Lactobacillus were significantly decreased (P < 0.05) in the medium-, and high-dose acrylamide (15 and 30 mg/kg) groups. But in the Lactobacillus casei treatment groups, Escherichia coli and Enterococcus faecalis were decreased, and Bifidobacterium and Lactobacillus were increased when compared with the medium-, and highdose acrylamide groups. Conclusion: Lactobacillus casei showed some protective effect on acrylamide-induced intestinal injury in rats. The underlying mechanism may be associated with the protection of intestinal mucosal barrier function and the regulation of the intestinal microbiota.