Research Article Culturable Bacterial Microbiota of the Stomach of Helicobacter pylori Positive and Negative Gastric Disease Patients Yalda Khosravi, 1 Yakhya Dieye, 2 Bee Hoon Poh, 3 Chow Goon Ng, 4 Mun Fai Loke, 1 Khean Lee Goh, 5 and Jamuna Vadivelu 1 1 Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia 2 Vice-chancellor’s Oice, University of Malaya, 50603 Kuala Lumpur, Malaysia 3 BP Diagnostics Centre Sdn Bhd, 30250 Ipoh, Perak, Malaysia 4 Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117545 5 Department of Medicine, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia Correspondence should be addressed to Jamuna Vadivelu; jamuna@ummc.edu.my Received 12 May 2014; Revised 16 June 2014; Accepted 16 June 2014; Published 3 July 2014 Academic Editor: Fernando Rodrigues Copyright © 2014 Yalda Khosravi et al. his is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Human stomach is the only known natural habitat of Helicobacter pylori (Hp), a major bacterial pathogen that causes diferent gastroduodenal diseases. Despite this, the impact of Hp on the diversity and the composition of the gastric microbiota has been poorly studied. In this study, we have analyzed the culturable gastric microbiota of 215 Malaysian patients, including 131 Hp positive and 84 Hp negative individuals that were afected by diferent gastric diseases. Non-Hp bacteria isolated from biopsy samples were identiied by matrix assisted laser desorption ionization-time of light mass spectrometry based biotyping and 16SrRNA sequencing. he presence of Hp did not signiicantly modify the diversity of the gastric microbiota. However, correlation was observed between the isolation of Streptococci and peptic ulcer disease. In addition, as a irst report, Burkholderia pseudomallei was also isolated from the gastric samples of the local population. his study suggested that there may be geographical variations in the diversity of the human gastric microbiome. Geographically linked diversity in the gastric microbiome and possible interactions between Hp and other bacterial species from stomach microbiota in pathogenesis are proposed for further investigations. 1. Introduction A luxurious microbial lora that is important to the health and well-being of the host inhabits human gastrointesti- nal tract. Gut microbiota contributes to several functions including energy harvest and storage from the diet [1], development and regulation of the gut-associated mucosal immune system [2], regulation of the central nervous sys- tem [3], detoxiication of xenobiotics and carcinogens, and protection against colonization by pathogens [4]. he gut microbiota is acquired early ater birth and is shaped by several factors including diet [5], genetic background, and environment [6]. Its composition and complexity can be modiied by physiological changes such as aging [5] and pregnancy [7]. Fluctuations of the gut microbiota can also result from antibiotic treatment, metabolic, immunological, or infectious diseases [6]. In particular, chronic infectious and noninfectious diseases can imprint long-lasting changes of the gut microbiota that greatly impact gut homeostasis and can favor the development of other diseases [4]. he analysis of the gut microbiota and its variation is emerging as a medical approach that will be used in the prevention or treatment of diseases. Helicobacter pylori (Hp) is a major pathogen that has been associated with humans for over 60,000 years [8]. It is estimated that more than half of the world population is infected by Hp [9]. However, Hp infection remains asymp- tomatic in the majority of the cases. In a small proportion of individuals, the infection leads to diferent diseases including peptic ulcers, chronic atrophic gastritis, gastric cancers, and gut lymphoma [10, 11]. Interestingly, Hp is also believed to confer on its host a protection against certain diseases Hindawi Publishing Corporation e Scientific World Journal Volume 2014, Article ID 610421, 10 pages http://dx.doi.org/10.1155/2014/610421