一株植物乳杆菌Lp3对高脂模型大鼠的益生作用

Probiotic role of Lactobacillus plantarum Lp3 on hyperlipidemia rats

摘要:

[目的]本研究通过构建大鼠高脂结构模型来探究一株植物乳杆菌Lp3的益生作用。[方法]植物乳杆菌Lp3筛选自青藏高原地区传统发酵的牦牛酸奶，初步认定Lp3是一株具有良好耐受力的降胆固醇菌株，且体外益生特性突出，本研究通过建立高脂SD大鼠模型，在饲喂试验动物高脂饲料的同时灌胃植物乳杆菌Lp3，来确定该菌株对试验动物血脂的影响效果，并同时研究其对大鼠肠道菌群、粪便水分、粪便中胆固醇和胆汁酸含量的影响，以及对肝脏组织中的胆固醇（TC）和甘油三酯（TG）的影响。[结果]结果表明，植物乳杆菌Lp3对大鼠没有任何明显的毒副作用，对高脂模型大鼠具有良好的降血脂效果。饲喂高脂饲料并灌喂乳酸菌Lp3组大鼠（HL）的血清总胆固醇、甘油三酯和低密度脂蛋白胆固醇含量较饲喂高脂饲料组（HC）显著减少（P<0.05），但是高密度脂蛋白胆固醇的含量变化并不明显。HC组大鼠与HL组及饲喂普通日粮组（对照组）大鼠相比较，HC组大鼠粪便中大肠杆菌数量明显增加，双歧杆菌、乳杆菌数量明显减少。但是灌胃乳酸菌的HL组大鼠的粪便中乳杆菌数略高于对照组，大肠杆菌和双歧杆菌数量和对照组大鼠的基本一致。表明植物乳杆菌Lp3具有维持肠道菌群平衡的作用。此外灌胃乳酸菌后HL组大鼠粪便含水量比HC组要高6.44%。HC组大鼠肝脏组织中胆固醇和甘油三酯要显著高于HL组（P < 0.05），说明Lp3可以减少脂类物质在肝脏组织中的沉积。从肝脏组织切片来看，也可以得出上述结论。[结论]结果表明本研究所筛选的植物乳杆菌Lp3对高脂大鼠具有值得深入研究的益生作用。

关键词:乳酸菌;大鼠;降胆固醇;益生作用

Abstract:

[Objective] In this study, we explored the probiotic effect of Lactobacillus plantarum Lp3 on fatty rats.[Methods] In vitro Lp3 with high hypocholesterolemic effects was isolated from Yak yogurt in Qinghai Tibet Plateau. We established a Sprague Dawley rat model of hyperlipidemia to determine the effect of the strain on blood lipids in experimental animals, and to study the effects on the intestinal flora, fecal moisture, cholesterol levels and bile acids of fecal, and the changes of cholesterol and triglycerides levels in the liver of SD rats. Thirty rats were assigned to three groups and fed either a normal or a high-cholesterol diet. The LAB treated group received the high-cholesterol diet supplemented with Lactobacillus plantarum Lp3.[Results] Lactobacillus plantarum Lp3 had no obvious side effects in rats and had a good cholesterol-lowering effect in high fat model rats. Lactobacillus plantarum Lp3 could significantly reduce serum total cholesterol, triglycerides and LDL-cholesterol levels in rats fed a high fat diet compared with the control group (P<0.05), but no difference was observed in high-density lipoprotein cholesterol. Compared with other two groups of rats, number of E. coli in feces of high fat fed rats group (HC) had obvious increase, the number of Bifidobacterium and Lactobacillus decreased significantly. But in high fat and LAB fed rats group (HL), the number of Lactobacillus in the feces was slightly higher than that in control group. The number of E. coli and Bifidobacteria were almost same as that in the control group. The results indicated that Lp3 could maintain the balance of intestinal flora and increase the moisture content in feces about 6.44% compared with HC group. Cholesterol and triglyceride in the liver tissue of the high fat fed rats group (HC) were significantly higher than high fat and LAB fed rats HL group (P<0.05). Lp3 could reduce lipid deposition in liver tissue. From histology of liver steatosis, we could also draw out the above conclusion. Cholesterol and bile acid contents in feces of HL group were higher than the HC group.[Conclusion] Lactobacillus plantarum Lp3 has probiotic potentials.

Key words:lactic acid bacteria;rats;cholesterol-lowing;the probiotic effect