人体消化道高抗逆性双歧杆菌的筛选

Screening of Bifidobacterium Strains with High Stress Resistence to Gastrointestinal Environment

双歧杆菌是人体肠道的一种微生态调节剂,对人体消化道环境的抗逆性是其发挥抗肠道感染作用的关键。分别利用激光共聚焦显微镜,测定五株分别来源于药物和婴儿粪便的双歧杆菌对结肠癌细胞Caco-2的黏附性,再通过耐酸和耐胆汁盐初筛,模拟胃液和模拟肠液复筛,筛选出消化道高抗逆性双歧杆菌L-1,其对Caco-2的黏附数为166±21黏附菌数/细胞;在pH3.0模拟胃液中作用2 h后的存活率为72%;在胆汁盐浓度为0.2%的模拟肠液中24 h,其存活率为14%。结果表明,五株双歧杆菌肠道抗逆性有所不同,L-1菌株消化道抗逆性能力最好,可用做微生态制剂菌株。

Bifidobacteria was an important probiotics and used in the dairy industry to relieve and treat many intestinal disorders, whose stress tolerance to human gastrointestinal environment played a key role of exerting a barr/er effect against enteropathogens. Five bifidobacterium strains were isolated from drugs and infant feces,whose adhesiveness on human colon cancer Caco-2 cell in vitro were examined by scanning confbcal laser microscopy. The hardest stress tolerance of strains L-1 was screened and selected by preliminary screening and second selection, the adherent level was 166±21 adhering/cell on Coco-2 cell, survival rate was 72% when grown in simulated gastric fluid at pH3.0 for 2 h and was 14% when grown in simulated intestinal fluid containing 0.2% bile salt for 24 h. The results indicated that the ability to tolerate gastroenteric environment and the adhesive capacity to Coco-2 cell among Bifidobacterium strains were different. The strains L-1 had several aspects of advantages and may be regarded as potential prohioties.