具有α-葡萄糖苷酶抑制活性的益生乳酸菌筛选

Screening for Potential Probiotic Lactic Acid Bacteria Strains Based onα-glucosidase Inhibitory Activity

利用α-葡萄糖苷酶抑制剂体外筛选模型,分析了来源于传统乳制品的10株乳杆菌对猪小肠提取的α-葡萄糖苷酶的抑制活性;对这些菌株的基本益生特性,包括对人工模拟胃肠液的耐受性及对肠上皮细胞的粘附性等进行了评价;最后,通过Caco2细胞建立的Transwell模型分析了乳杆菌对人肠道α-葡萄糖苷酶活性及其基因表达的影响。结果表明,这10株乳杆菌对猪小肠提取的α-葡萄糖苷酶均具有不同程度的抑制作用;乳杆菌的α-葡萄糖苷酶抑制活性在菌株生长的对数期或稳定期达到高峰,随后出现下降的趋势;结合菌株的基本益生特性评价发现,有3株具有较高抑制活性的乳杆菌能够耐受人工模拟的胃肠液,并具有较强的黏附肠上皮细胞HT-29的能力;由Transwell模型发现,乳杆菌能同时抑制α-葡萄糖苷酶的活性及基因表达量。研究表明,筛选出的3株乳杆菌(副干酪乳杆菌L14和Z3-11以及植物乳杆菌NL42)均具有较高的α-葡萄糖苷酶抑制活性和较好的益生特性,可作为潜在的辅助降血糖的益生菌株。

Lactic acid bacteria strains(LAB)are regarded as safe food-grade microorganism and have been used in fermented food production and preservation for a long history.Some of the LAB strains are considered as probiotics and have the potential to regulate diabetes.In order to screen potential hypoglycemic probiotic strains in vitro,10 Lactobacillus strains isolated from traditional dairy products were determined for the inhibitory activity againstα-glucosidase from porcine intestine.The basic features of probiotics,including gastrointestinal fluid tolerance and cell adhesion,were also investigated.Some strains were selected for further study of their effects onα-glucosidase activity and gene expression level by Transwell model established by Caco2 cells.The results showed that all the 10 strains showed different degrees ofα-glucosidase inhibitory activity,which peaked at the logarithmic or stationary phase of the strains growth,and then decreased.The evaluation of the basic features of probiotics suggested that three strains with higherα-glucosidase inhibitory activity showed tolerance to the simulated gastrointestinal fluid and strong HT-29 cell adhesion.The Caco2 cells model showed that Lactobacillus strains could both inhibitα-glucosidase activity and its mRNA expression.The selected three Lactobacillus strains,including Lactobacillus paracasei strains L14 and Z3-11,and Lactobacillus plantarum strain NL42 displayed highα-glucosidase activity and good probiotic properties and may serve as potential probiotics for the auxiliary management of diabetes.