%0 Journal Article %T Oral Cavity as an Extragastric Reservoir of Helicobacter pylori %A Arwa Al Sayed %A Pradeep S. Anand %A Kavitha P. Kamath %A Shankargouda Patil %A R. S. Preethanath %A Sukumaran Anil %J ISRN Gastroenterology %D 2014 %R 10.1155/2014/261369 %X Background. Several studies were reported on the prevalence, and relationship between the existence of Helicobacter pylori (H. pylori) in oral cavity and in stomach of patients. The purpose of this study was to systematically review the existing literature on the presence of H. pylori in the oral cavity and its link to gastric infection, the existence of coinfection, and the impact of anti-H. pylori therapy on the dental plaque and vice versa. Method. Two authors independently searched the Medline, EMBASE, Cochrane Library, Web of Science, Google Scholar, and Scopus databases for relevant studies. The articles were analyzed critically and all qualified studies were included. The search was carried out by using a combined text and the MeSH search strategies: using the key words Helicobacter, Helicobacter pylori, and H. pylori in combination with dental plaque, periodontitis, and oral hygiene. Results. The data was presented in 8 tables and each topic separately discussed. Conclusion. Based on the systematic review of the available literature on H. pylori infection and its presence in the oral cavity, it can be concluded that dental plaque can act as a reservoir, and proper oral hygiene maintenance is essential to prevent reinfection. Due to the diversified methods and population groups involved in the available literature, no concrete evidence can be laid down. Further studies are necessary to establish the role of H. pylori in the oral cavity and its eradication on preventing the gastroduodenal infection. 1. Introduction Helicobacter pylori (H. pylori) is one of the most common bacterial infections in humans [1]. The presence of the organism H. pylori (initially termed Campylobacter pyloridis) in the antral mucosa of humans was first reported in 1983 [2]. H. pylori has been closely linked to chronic gastritis, peptic ulcer, gastric cancer, and mucosa-associated lymphoid tissue (MALT) lymphoma [3, 4]. The International Agency for Research on Cancer of the World Health Organization (WHO) has designated H. pylori as a Group 1 carcinogen [5]. Besides gastrointestinal diseases, recent data seems to suggest a possible association of this microorganism with other conditions such as anemia [6], altered serum levels of lipoproteins [7], and coronary atherosclerosis [8]. Although H. pylori is present in the stomach of about half of the worldĄŻs population, we do not yet clearly understand its transmission. Available data suggests that oral-oral and fecal-oral routes are the most likely routes of transmission of this organism [9, 10]. However, no extragastric %U http://www.hindawi.com/journals/isrn.gastroenterology/2014/261369/