Abstract 6135: Microbiome profiling through the various gastrointestinal environment of gastric cancer

Abstract The association between cancer and microbiome dysbiosis across anatomically related multiple body sites has not been comprehensively investigated. The purpose of our study is to profile microbial diversity and composition through the various gastrointestinal environment of gastric cancer (GC). We performed V3-V4 16S rRNA gene sequencing analysis for matched samples of gastric tumor, normal gastric mucosa, gastric juice and stool from 30 GC patients. Amplicon sequence variant (ASV) profile was compared among the four body sites at genus level. In this study, we found that mean alpha diversity was lowest in normal gastric mucosa and stool exhibited the largest amount of alpha diversity compared with others. Beta-diversity analysis showed significant differences in microbiota composition for each sample. The microbiome dysbiosis was significantly independent in gastrointestinal environment of gastric cancer. Helicobacter abundance in tumor tissue was significantly lower than in matched normal tissue and gastric juice while the trend was opposite for Lactobacillus. Additionally, the level of Helicobacter was considerably lower in patients with lymphatic invasion. The bacterial community that significantly correlated with tumor samples compared to normal mucosa, gastric juice, and stool were 49, 27, and 11 genus, respectively. Lactobacillus and Delftia had higher abundance and Rothia and Collnsella had lower abundance in tumor tissue compare with normal mucosa. Especially, Delftia was seen only in the tumor tissue not normal gastric mucosa, gastric juice and stool. Pentose phosphate pathway was significantly enriched in tumor tissue and normal mucosa. There is a unique microbiome pattern through the various gastrointestinal environment of gastric cancer. Our analysis shows enriched Delftia abundance only in the tumor tissue except other sample type. Citation Format: Jieun Lee, Sunguk Shin, Seung-been Lee, Yieri Yoo, Sangjun Lee, So Hyun Kang, Eunju Lee, Young Suk Park, Sang-Hoon Ahn, Kyoung Un Park, Hyung-Ho Kim, Nak Jung Kwon, Yun-Suhk Suh. Microbiome profiling through the various gastrointestinal environment of gastric cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 6135.