title: Helicobacter pylori in the oral cavity and gastric mucosa: a meta-analysis.
abstract: BACKGROUND
  Helicobacter pylori have been found in the oral cavity and stomach. This study is to establish whether there might be any associations between isolates of H. pylori in the oral cavity and those in the stomach by meta-analysis.
  
  
  METHODS
  Studies reporting raw data on the prevalence of H. pylori infection in the oral cavity in gastric H. pylori-positive and H. pylori-negative patients, in patients with gastroesophageal diseases, and in healthy individuals and studies reporting data on the eradication rate in the oral cavity or stomach, published in the English language, were identified through MEDLINE and EMBASE up to May 2010.
  
  
  RESULTS
  The prevalence of H. pylori infection in the oral cavity in gastric H. pylori-positive patients was significantly higher (45.0%) than that in gastric H. pylori-negative patients (23.9%). The pooled odds ration (OR) was 3.61 and the 95% CI was 1.91-6.82 (P < 0.0001). Different diagnostic methods produced different pooled ORs with PCR the highest (OR = 5.11, 95% CI: 2.08-12.54, P = 0.0004) and rapid urease test (RUT) the lowest (OR = 2.00, 95% CI: 0.80-5.00, P = 0.14). The 44.8% (91/203) prevalence of H. pylori infection in the oral cavity in patients with clinical and/or histological gastroesophageal diseases was significantly higher than the 13.2% (21/159) in patients with non-ulcerous dyspepsia or healthy controls (OR = 5.15, 95% CI: 2.97-8.92, P < 0.00001). The eradication efficiency in stomach is 85.8% (187/218), while in oral cavity it is only 5.7% (9/158). The OR is 55.59, P < 0.00001.
  
  
  CONCLUSIONS
  There is a close relation between the infection of H. pylori in the oral cavity and stomach. H. pylori in the oral cavity are more difficult to be eradicated than in the stomach. It may be a source of reinfection.
authors.affiliation: Department of Microbiology, Peking University Health Science Center, Beijing, China. zouqinghua@bjmu.edu.cn
authors.forename: Qing-Hua
authors.initials: QH
authors.lastname: Zou
authors.forename: Ren-Qing
authors.initials: RQ
authors.lastname: Li
mesh_terms: D005753:Gastric Mucosa / Q000382:microbiology*; D016481:Helicobacter Infections; D016480:Helicobacter pylori / Q000302:isolation & purification*; D006801:Humans; D009055:Mouth / Q000382:microbiology*; D009061:Mouth Mucosa / Q000382:microbiology*; D016017:Odds Ratio