Characterization of Gastric Microbiota in Gastric Cancer Patients

Introduction & Aim: Gastric carcinoma (GC) is the second cause of death from cancer worldwide. Helicobacter pylori infection is the single strongest risk factor for gastric cancer. Recently, advances in DNA sequencing technology have confirmed the presence of other bacteria in the stomach. It seems that the bacteria may play a role in gastric cancer development. In this study, we characterized the gastric microbiota in gastric cancer patients and compared it in dyspeptic patients as control. Methods About 8 formalin-fixed paraffin-embedded (FFPE) gastric adenocarcinoma samples were obtained from department of Pathology of Imam Reza hospital, Tabriz, IRAN. DNA extraction was performed using a modified salting out method. The 16S rRNA gene was amplified by PCR using specific primers. Gastric microbiota was analyzed by pyrosequencing of the 16S rRNA gene. Results: The results showed that in addition to H. pylori, other bacteria from different genera including Streptococcus and Lactobacillus are also abundant in cancer patients in compression with dyspeptic patients. Conclusion: In the conclusion, it is thought that non-H. pylori bacteria can play role in cancer progression. They may accelerate cancer development through the cross-talking by H. pylori.