en Microbial pathogenesis Microbial pathogenesis Original article Original article <strong>Introduction.</strong> <em>Helicobacter pylori </em>infection is one of the primary etiological factors associated with gastric carcinogenesis. This study investigated the expression of microRNAs, miR-20a, miR-30a, miR-210, and miR-874, in <em>H. pylori</em>-infected patients with and without gastric cancer (GC) compared to healthy subjects.<strong> Methods.</strong> Total RNA was extracted from the plasma of <em>H. pylori</em>-infected GC patients (n=40), <em>H. pylori</em>-infected patients (n=40), and healthy individuals (n=12). The expression of microRNAs was analyzed using a reverse transcription-quantitative real-time PCR (RT-qPCR) technique.<strong> Results.</strong> The miR-20a, miR-30a, miR-210, and miR-874 exhibited higher overexpression in <em>H. pylori</em>-infected GC patients than healthy persons (<em>P</em>=0.004, 0.033, 0.023, 0.024). The <em>H. pylori</em>-positive patients without GC also had higher miR-20a, miR-30a, and miR-210 levels than the healthy individuals (<em>P</em>= 0.013, 0.036, 0.032). There were no statistical differences between <em>H. pylori</em>-infected GC patients and <em>H. pylori</em>-infected patients without GC <strong>Conclusion.</strong> The microRNAs overexpression in <em>H. pylori</em>-infected patients with GC might be linked to <em>H. pylori</em> rather than GC<span dir="RTL">.</span> Therefore, these microRNAs can be helpful in <em>H. pylori</em> infection diagnosis rather than predicting GC. in <em>H. pylori</em>-infected patients. Gastric cancer, Helicobacter pylori, MicroRNAs, RT-qPCR 185 190 http://jommid.pasteur.ac.ir/browse.php?a_code=A-10-330-1&slc_lang=en&sid=1 Saba Hariri Monfared saba_hariri@yahoo.com 0000-0002-2322-5363 No Department of Biotechnology and Microbiology, Medicine Branch, Islamic Azad University, Tehran, Iran Mina Yaghoub Kazemi 0000-0003-1252-1033 No Fahimeh Nemati Mansoor f_nemati82@yahoo.com 0000-0003-3921-4682 No Department of Biotechnology, Medicine Branch, Islamic Azad University, Tehran, Iran Mahnaz Mohammadi mh_mohamadi@yahoo.com 0000-0002-3376-2162 Yes Department of Biology, Faculty of Biological Sciences, Islamshahr Branch, Islamic Azad University, Islamshahr, Iran