抗Hp嗜酸乳杆菌的筛选及其相关生物学特性的研究

Study on the correlated bionomics of the Lactobacillus acidophilus with Hp antagonistic activity

目的筛选对Hp抑制效应强的嗜酸乳杆菌菌株,并观察其生物学特性,为进一步开发根除Hp的生态治疗奠定基础。方法从120份粪便标本中分离出嗜酸乳杆菌,采用打孔法筛选具有Hp抑制效应的菌株,并在体外模拟胃及十二指肠环境观察这种菌株耐酸、耐胆盐的能力,同时用SPECT静态显像观察^99Tc^m标记的嗜酸乳杆菌在大鼠胃腔内存留时间。结果通过打孔法从62株嗜酸乳杆菌中筛选出16株对Hp具有抑制效应的菌株,其中2株抑制作用较强。在模拟胃环境中,两株菌株的存活率随着pH值的逐渐下降、培养时间的延长而逐渐下降,但在pH值为1.0的模拟胃液培养2小时,仍可保持一定存活率;两株菌株在胆盐浓度为0.03%～0.48%的模拟十二指肠液中,培养各时间段均具有较高生存率。灌饲30分钟后大鼠胃腔内^99Tc^m放射计数开始减少,180分钟内各段时间测得大鼠胃区^99Tc^m的放射活性计数均明显高于对照组（P〈0.05）,与测量局部胃黏膜组织放射性活度的结果相一致。结论研究中从人体消化道分离出2株在体外对Hp有较强抑制效应的嗜酸乳杆菌菌株,该菌株具有耐酸及耐胆盐的特征,并可以长时间在胃腔内存留,研究结果为进一步开发嗜酸乳杆菌生态治疗奠定了基础。

Objective：Human Lactobacillus acidophilus with strong Hp antagonistic activity was screened and studied bionomies in order to provide theory for treating Hp infection with biotherapeutic agents. Methods：The suspected strains of Lactobacillus acidophilus were isolated from the stools of 120 healthy persons and the strains having depressive effect of Hp were selected by punch method. Investigated the growth ability of the Lactobacillus acidophilus with strong Hp antagonistic activity in simulated gastric juice and duodenum juice in vitro. Observed the ^99Tc^m-labed Lactobacillus acidophilus transition with SPECT for 180 min after perfusing rats. Results：According punch method we identified 16 strains which had Hp antagonistic activity in 62 isolated Lactobacillus acidophilus, 2 strains among them had stronger depressive effect than others. When the gastric juice pH descended and culture time lasted in simulated gastric juice, the survival rate of the 2 strains decreasced. In the juice with pH 1.0 for 2 hours the 2 strains had well survival ability. The 2 selected strains had well survival ability in different bile salt concentiration raged from 0. 03% to 0. 48% simulated duodenum juice for 6 h. After perfusion 30 mins, the group＇s radioactivity of ^99Tc^m in the rats＇ stomach began to decrease. The radioactivity of experimental groups was signifanctly higher than contrtol groups in different time. The result agreed with the result of counting the intensity of radioactivity in gastric mucosa. Conclusion：The study selected 2 Lactobacillus acidophilus with strong antagonistic activity on Hp from human gastrointestinal tracts. These 2 strains could resist the gastric acid and bile salt of simulated gastrointestinal tracts environment, meanwhile it could persistence in stomach for long time. These data provided theory for the treating Hp infection with biotherapeutic agents.