Effect of Bile Reflux on Gastric Juice Microbiota from Patients with Different Histology

Bile reflux can influence the gastric environment by altering gastric acidity and possibly the composition of gastric microbiota. This study aimed to investigate the correlation between bile acids and microbial compositions in gastric juice among patients with various gastric pathologies. Gastric juice samples were collected from a total of 50 subjects, including 10 subjects undergoing endoscopic surveillance, 21 subjects with low-grade dysplasia, and 19 subjects with early gastric cancer. The subjects were categorized into three groups based on the endoscopic bile reflux (BR) grading system (BR grade 0, BR grade 1, and BR grade 2). We measured the concentration of primary and secondary bile acids and conducted microbiota profiling using 16S rRNA gene sequencing.