Abstract: Objective To investigate the effect of proton pump inhibitor (PPI) omeprazole on the composition of esophageal microbiota in rats with reflux esophagitis. Methods The rat model of reflux esophagitis was established by the method of pyloric partial ligation and complete anterior gastric ligation. Rats were randomly divided into sham operation control group, reflux esophagitis control group and PPI treatment group (omeprazole). One week after the operation, distilled water/omeprazole tablets were intragastric administration once a day and two pieces of lower esophageal mucosa were obtained 2 weeks later, one for bacteria 16S rDNA gene sequencing, and another for pathological examination. Results Six surviving rats in each group were selected. The abundance values of sham operation control, reflux esophagitis control and PPI treatment groups at the genus level were as follows:Peptostreptococcus 2.5%±0.5%, 1.7%±0.7% and 1.9%±0.5%; Helicobacter 1.5%±0.1%, 1.0%±0.5% and 1.2%±0.3%;Turicibacter 1.0%±0.2%, 0.5%±0.2% and 1.0%±0.4% (P＜0.05). The abundances of Peptostreptococcus, Helicobacter, and Turicibacterin the reflux esophagitis control group were signifi-cantly reduced than those in the sham operation control group. The pathological grades of reflux esophagitis (mild/moderate/severe) in reflux esophagitis control and PPI treatment groups were 0/4/2 and 5/1/0(P＜0.05). Conclusions There are moderate changes in the composition of esophageal microbiota in rats with reflux esophagitis,the proportion of beneficial bacteria reduced. After the treatment of PPI omeprazole, the esophageal mucosal injury is alleviated, the proportion of beneficial bacteria increased, and the composition of esophageal microbiota returns to normal.

Key words: reflux esophagitis, proton pump inhibitor, high-throughput DNA sequencing, esophageal microbiota