Dysbiosis in gastric mucosal microbiota associated with gastric carcinogenesis.

Abstract

381 Background: Gastric microbiota, including H. pylori, may play a role in the development of gastric cancer. This study aimed to investigate the gastric microbiota throughout the stages of gastric carcinogenesis, encompassing atrophic gastritis, gastric dysplasia, and gastric adenocarcinoma. Methods: From December 2021 to August 2023, we collected gastric mucosal tissue samples from patients with atrophic gastritis, gastric dysplasia, and early gastric cancer. Subsequently, we conducted 16S rRNA gene profiling through next-generation sequencing. We compared alpha-diversity and beta-diversity within each group and analyzed the taxonomic composition. Results: This study included a total of 98 patients, comprising 16 with atrophic gastritis, 23 with low-grade dysplasia, 15 with high-grade dysplasia, and 44 with early gastric cancer. The H. pylori infection status was comparable across all groups. While there was a difference in alpha diversity between tumor lesions and normal stomach lesions, it did not reach statistical significance. Notably, Phyllobacterium was dominant in early gastric cancer, Prevotella in high-grade dysplasia, and Kocura in low-grade dysplasia. Furthermore, within the early gastric cancer group, Bacillus was widely distributed in cases of undifferentiated type adenocarcinoma. Conclusions: The analysis of microbiota collected from Korean stomach tissue revealed distinct microbial distributions across the various stages of gastric carcinogenesis.