中文摘要：

目的通过小鼠动物模型,检测幽门螺杆菌感染后食道下端菌群的变化,探讨其与食道下端疾病发生的关系。方法将30只BALB/C小鼠随机均分为阴性对照组和感染组。感染组通过灌喂幽门螺杆菌菌液建立动物感染模型,两组小鼠均在末次灌喂菌液4周后同时处死,取食道下端组织提取细菌的DNA,以原核生物16S rDNAV6区通用引物采用聚合酶链反应-变性梯度凝胶技术（PCR-DGGE）对V6区进行扩增,用Quantity-One 1-DAnalysis software.对DGGE图谱进行菌群分析,并将DGGE图谱上的组间差异条带用16S rDNAV6区引物分别扩增后,DNA测序,BLAST比对分析。

英文摘要：

Objective To explore the relationship between Helicobacter pylori （H. pylori） infection and lower esophageal diseases in light of the changes of the bacterial flora in the lower esophagus. Methods Thirty BALB/C mice were randomized into negative control group and H. pylori infection group, and in the latter group, the mice were subjected to intragastric administration of solution containing H. pylori. After 4 weeks of administration, all the mice were sacrificed, and the V6 areas in 16S rDNA were amplified from the bacterial DNA extracted from the lower esophagus using polymerase chain reaction-denaturing gradient gel electrophoresis. The bacterial floras were analyzed on DGGE atlas with Quantity-One 1-D analysis software, and the differential bands between the two groups were amplified using a 16S rDNA v6 area primer followed by DNA sequencing and BLAST analysis. Results DGGE finger-prints showed a significantly greater number of DNA bands in the infection group than in the negative control group （P〈0.01）. The diversity index and richness index were also significantly higher in the infection group （0.01〈P〈0.05）. Bacterium cluster class analysis well separated the dendrogram in the infection group. Principal component analysis showed that different groups of bacteria gathered in different locations, and BLAST analysis revealed the presence of special bacteria in the infection group. Conclusions In normal mice, Lactobacillus and the Bacteroides are the predominant bacterial flora colonizing in the lower esophagus, and Staphylococcus, Acinetobacter and Bacteridium become the predominant bacteria after H. pylori infection.