Is Helicobacter pylori resident or transient in the human oral cavity?

Abstract

Helicobacter pylori colonizes the stomachs of at least half of the world's human population. The role of the oral cavity in this colonization is not clear and there are, to date, no comprehensive data that clearly demonstrate the isolation of this bacterium from the oral cavity. The aim of this study was to evaluate the prevalence of H. pylori in the oral cavity of 15 patients who tested positive for H. pylori. A comprehensive dental examination of all patients was conducted. Samples were taken from supragingival and subgingival plaque, saliva, periapical exudates and tongue swabs. All samples were taken before the application of antibiotics. A total of 163 oral samples were investigated by PCR using two different H. pylori-specific primer pairs. A PCR inhibition control using a modified plasmid was always included for the most specific primer pair. In addition, a culture technique was used to confirm PCR results. Despite a PCR detection limit of 10 2 bacteria ml "1, out of 14 patients, H. pylori could not be detected in any of the samples taken. In one patient, H. pylori-positive PCR signals were obtained in two samples using only one primer pair. H. pylori could not be cultivated from these two PCR-positive samples; therefore, no correlation to oral colonization status could be established. This study challenges the misleading preconception that H. pylori resides in the human oral cavity and suggests that this bacterium should be considered transient and independent of the oral status. To date, positive PCR results for H. pylori in the oral cavity have been overestimated and not critically interpreted in literature.

Association between Helicobacter pylori gastritis and dental diseases: A cross‐sectional, hospital‐based study in Eastern Saudi Arabia

“…In another study with patients positive for gastric H. pylori , plaque, and saliva samples were tested for H. pylori using PCR. Samples were all negative and the authors suggested that H. pylori is transient in the mouth …”

Reducing uncertainty in estimating associations of oral exposures with Helicobacter pylori serology in the general population

“…RDP was considered neither in a large population‐based study (Dye et al., ) nor in a review on the “oral cavity as an extragastric reservoir of H. pylori ” (Al Sayed et al., ). Writing “the oral cavity is not a reservoir for H. Pylori in infected patients” (Al‐Ahmad et al., ), absence of evidence was wrongly interpreted as evidence of absence (Altman & Bland, ). Thus, selection and information bias for the relation between H. pylori outcomes and RDP may have been introduced for several reasons in various studies.…”

Detection of Helicobacter pylori in patients with head and neck cancer: Results from a prospective comparative study combining serology, polymerase chain reaction, and rapid urease test

“…This strongly suggests that H. pylori was not present in the UADT biopsy samples at the time of the biopsy. In the literature, reported PCR detection rates for H. pylori in the UADT range from 0% to 100% in adults, with most studies situated between these 2 extremes . Many factors may be responsible for this discrepancy: first, the targeted genes and primers used to detect H. pylori vary widely.…”

“…H. pylori containing liquids are thought to infect new individuals orally, implying that H. pylori must be transiently present in the upper aerodigestive tract (UADT) . The presence and potential impact of H. pylor i in the UADT is subject to debate . H. pylori has not only been associated with inflammatory conditions, which include aphthous ulcers, chronic pharyngitis, and dental plaques, but also with malignancy, such as head and neck squamous cell carcinoma (HNSCC) …”