Published online Feb 6, 2016. doi: 10.4292/wjgpt.v7.i1.126
Peer-review started: April 30, 2015
First decision: July 25, 2015
Revised: October 16, 2015
Accepted: November 10, 2015
Article in press: November 11, 2015
Published online: February 6, 2016
Helicobacter pylori (H. pylori) has long been found to cause gastric diseases such as gastritis, gastric ulcers and gastric cancer. The transmission medium of this bacterium has yet to be determined, though several studies have speculated that the oral cavity is a reservoir for H. pylori. Others have also reported that the oral cavity may be a source of both transmission and gastric reinfection; however, such results are controversial. We reviewed the literature and selected studies that report an association among H. pylori detections in the oral cavity (dental plaque, saliva, tongue, tonsil tissue, root canals, oral mucosa) in humans and in animals, as well as in the human stomach. The oral cavity may be considered the main reservoir for H. pylori. There are a correlations between H. pylori infection in the oral cavity and periodontal disease, oral tissue inflammation, H. pylori transmission, and gastric reinfection. We believe that the mouth is a reservoir and that it plays a crucial role in both H. pylori transmission and gastric infection.
Core tip: This review focuses on some aspects of infection and reinfection by Helicobacter pylori (H. pylori), particularly in the possible reservoirs of this bacterium. It also explores the association between gastric infection and these reservoirs. In addition, this review highlights possible reservoirs in animals and some routes of infection, and it considers the techniques used to diagnose this bacterium in different environments. The difficulty in accessing bacteria in reservoirs is a problem for H. pylori eradication in particular, and new discoveries in this field will contribute to the understanding of H. pylori infection mechanisms.