降胆固醇乳酸菌的筛选及其与山楂的体外协同降脂作用

Screening of cholesterol-lowering lactic acid bacteria and its in vitro synergistic lipid-lowering effect with hawthorn

高血脂及其引发的心血管疾病严重威胁人们的健康,乳酸菌和中药的降血脂功效成为研究热点.为了开发新的降脂途径,通过筛选降胆固醇乳酸菌,并探究其与中药的联合降脂作用,旨在提高二者现有的降脂效果.从酸奶、泡菜和青贮饲料中分离乳酸菌,研究其降胆固醇能力与益生特性,并通过主成分分析法,综合评价获得具有潜在应用价值的降胆固醇乳酸菌,进一步将其与降脂中药山楂联合发酵,研究其发酵液体外协同降脂效果.分离得到的90株乳酸菌中,初筛得到18株胆固醇去除率高于35%的乳酸菌.经主成分分析法比较得到9株高于商业对照菌株Lactobacillus rhamnosus GG的乳酸菌,其中Lactobacillus acidophilus JY20和JY41效果最好.将其与山楂混合发酵后,与降脂有关的活性成分含量及胆固醇和胆盐吸附能力显著提高.通过熵权法综合评价发现,山楂粉经JY20或JY41发酵后,体外降脂活性显著提高,分别提高了5.92倍、6.08倍.本研究表明降胆固醇乳酸菌与山楂的联合使用可以提高体外降脂效果,结果可为开发新的降脂方法提供新思路.

Hyperlipidemia and cardiovascular diseases caused by hyperlipidemia are seriously detrimental to human health. Lactic acid bacteria and traditional Chinese medicine(TCM) have become research hotspots in lipid-lowering. To develop a new lipid-lowering method, cholesterol-lowering lactic acid bacteria was screened and its lipid-lowering effect combined with hawthorn was explored for a better lipid-lowering effect than the current ones. Firstly, lactic acid bacteria were isolated from yoghurt, kimchi, and green storage fodder for their cholesterol-lowering ability and their probiotic properties were studied. Then, principal component analysis(PCA) was used to evaluate them comprehensively to obtain valuable cholesterol-lowering lactic acid bacteria. Furthermore, hawthorn was fermented with the cholesterol-lowering lactic acid bacteria, and the in vitro synergistic lipid-lowering effect of the fermentation broth was studied. Among the 90 isolated strains of lactic acid bacteria, 18 strains were initially screened that had a cholesterol removal rate over 35%. Nine strains of cholesterol-lowering lactic acid bacteria were further obtained by PCA and compared with the commercial strain Lactobacillus rhamnosus GG, among which Lactobacillus acidophilus JY20 and JY41 were the most potential lipid-lowering strains. After the hawthorn was fermented by Lactobacillus acidophilus JY20 or JY41, the contents of active components in hawthorn that are related to lipid-lowering and the adsorption capacity of cholesterol and bile salts significantly increased. By using the entropy method, the synergistic effect of lipid-lowering effect was comprehensively evaluated, indicating that the in vitro lipid-lowering effect of the combined fermentation of hawthorn with JY20 or JY41 were significantly increased by 5.92 and 6.08 times, respectively. The results showed that the combination of the cholesterol-lowering lactic acid bacteria and hawthorn could improve the in vitro synergistic lipid-lowering effect and provide a new idea for developing lipid-lowering methods.