长寿人群肠道具有降胆固醇特性益生菌的筛选

Screening of cholesterol- reducing probiotic isolated from the intestine of the longevity crowd in vitro

从长寿人群肠道内筛选出降胆固醇性能较好的益生菌株,并对其进行鉴定。通过人工模拟胃、肠道环境,研究分离自江苏如皋长寿人群肠道乳酸菌的耐酸耐胆盐能力,并研究其体外降胆固醇能力。结果表明,菌株f5在pH值为2.0和pH值为3.0的人工胃液中经过3 h的存活率为37.01%和68.55%,5 h后存活率为10.28%和23.39%;在人工肠液中1.5 h存活率为72.94%,3 h后存活率为46.84%;在0.1%,0.3%及0.5%胆盐环境中的耐受力分别为24.11%,20.31%和19.92%;在0.1%的胆盐质量分数下其对胆固醇降解率最高为63.73%。结论:菌株f5具有较强的耐酸耐胆盐能力,且对胆盐的耐受性与其降胆固醇能力之间存在显著正相关性,质量分数为0.1%胆盐是乳酸菌发挥降解胆固醇能力的最佳质量分数。经16S rRNA鉴定,菌株f5为发酵乳杆菌(Lactobacillus fermentum)。

To screen and identify cholesterol-reducing probiofic strains with better performance from the intestine of the longevity crowd. The tolerance to acid and bile salt, and the ability of cholesterol- reducing of 11 LAB isolated from the human intestine ofJiangsu Rugao longevity poptflations were studied by imitating stomach, intestinal environment. The survival rate of strai＇ns f5 at pH 2.0 and pH 3.0 in artificial gastric fluid after 3 h was 37.01% and 68.55%,the survival rate was 10.28% and 23.39% after 5 h; the survival rate of strains f5 in artificial intestinal fluid after 1.5 h and 3h were 72.94% and 46.84%, respectively; the tolerance to 0.1%,0.3% and 0.5% bile salt environment were 24.11%-20.31% and 19.92%, respectively. Its cholesterol degradation rate was the highest by 63.73% at 0.1% bile salt concentration. Strains 15 had strong tolerance to acid and bile salt, and it had a significant positive correlation between bile salt tolerance and cholesterol- reducing abil- ity, 0.1% bile salt concentration was an optimal concentration of cholesterol degradation. Strains f5 was LactobaciUus fermentum identified by 16S rRNA.