OBJECTIVETo 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.

METHODSThirty 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.

RESULTSDGGE 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

CONCLUSIONIn 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.