Abstract 3257: Molecular characterization of the human stomach microbiota in gastric cancer patients

Abstract

Abstract Background Helicobacter pylori (Hp) is the primary cause of gastric cancer but we know little of its relative abundance and other microbes in the stomach, especially at the time of gastric cancer diagnosis. Here we characterized the taxonomic and derived functional profiles of gastric microbiota in 157 non-malignant gastric tissue samples from two different sets of gastric cancer patients, and compared them with microbial profiles of oral, stool, nasal, vagina and skin samples from Human Microbiome Project. Results We show that Hp is the most abundant member of gastric microbiota in both Chinese and Mexican samples (51% and 24% respectively), followed by the genera commonly seen in the oral microbiota. Taxonomic (phylum) profiles of stomach microbiota largely resembled oral microbiota when the Helicobacter reads were removed. The functional profiles of stomach microbiota, however, were distinct from those found in other body sites and had higher inter-subject dissimilarity. Gastric microbiota composition did not differ by Hp colonization status or stomach anatomic site, but did differ between paired non-malignant and tumor tissues in either Chinese or Mexican samples. Conclusions Our study is the first to show that Hp is the dominant member of the gastric microbiota in many gastric cancer patients rather than diminished or depleted as traditionally believed. Our results provide insights on the gastric microbiota composition and function in gastric cancer patients, which may have important clinical implications. Citation Format: Guoqin Yu, Javier Torres, Nan Hu, Rafael Medrano-Guzman, Roberto Herrera-Goepfert, Michael S. Humphrys, Lemin Wang, Chaoyu Wang, Ti Ding, Jacques Ravel, Philip R. Taylor, Christian Abnet, Alisa Goldstein. Molecular characterization of the human stomach microbiota in gastric cancer patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3257. doi:10.1158/1538-7445.AM2017-3257