人体消化道高抗逆性双歧杆菌的筛选

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Caeo-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2h后的存活率为72％；在胆汁盐浓度为0．2％的模拟肠液中24h，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。

Screening of Bifutobacterium Strains with High Stress Resistence to Gastrointestinal Environment

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.