Colonization ofHelicobacter pyloriin the oral cavity – an endless controversy?

Abstract

Helicobacter pylori is associated with chronic gastritis, gastric or duodenal ulcers, and gastric cancer. Since the oral cavity is the entry port and the first component of the gastrointestinal system, the oral cavity has been discussed as a potential reservoir of H. pylori. Accordingly, a potential oral-oral transmission route of H. pylori raises the question concerning whether close contact such as kissing or sharing a meal can cause the transmission of H. pylori. Therefore, this topic has been investigated in many studies, applying different techniques for detection of H. pylori from oral samples, i.e. molecular techniques, immunological or biochemical methods and traditional culture techniques. While molecular, immunological or biochemical methods usually yield high detection rates, there is no definitive evidence that H. pylori has ever been isolated from the oral cavity. The specificity of those methods may be limited due to potential cross-reactivity, especially with H. pylori-like microorganisms such as Campylobacter spp. Furthermore, the influence of gastroesophageal reflux has not been investigated so far. This review aims to summarize and critically discuss previous studies investigating the potential colonization of H. pylori in the oral cavity and suggest novel research directions for targeting this critical research question.

Analysis of oral microbiota alterations induced by Helicobacter pylori infection and vonoprazan‐amoxicillin dual therapy for Helicobacter pylori eradication

“…9 Helicobacter pylori has been detected as positive in oral samples using molecular methods, immunological methods or culture methods, and the oral cavity has been discussed as a potential reservoir of H. pylori. 10 The oral microbiota promotes the colonization of H. pylori through coaggregation, symbiotic biofilm formation, and endosymbiosis 11 ; however, whether H. pylori is resident or transient in the oral cavity must be clarified. Li et al 12 demonstrated that different oral community structures exist between H. pylori-positive and H. pylori-negative groups using high-throughput sequencing of saliva samples.…”

Oral Microbiota, a Potential Determinant for the Treatment Efficacy of Gastric Helicobacter pylori Eradication in Humans

“…The coccoid form is a quiescent state of H. pylori in the oral cavity and could not be resurrected in the bacterial culture medium. In contrast, the spiral form of H. pylori in the stomach can be found ( Mao et al 2021 ). More importantly, the coccoid H. pylori trigger the alternations of the gastric tissues when they are gavaged into the stomach for two weeks ( Cellini et al 1994 ).…”

DNA diagnostics for reliable and universal identification of Helicobacter pylori

“…The oral cavity is as suitable for a H . pylori reservoir as the stomach in adults[ 18 ], as are inflamed teeth (pulp) in children[ 18 ], but this is still a controversial issue[ 15 , 35 , 50 ]. It remains unclear whether H .…”

“…It remains unclear whether H . pylori colonizes the oral cavity residentially, transiently, or at all[ 35 ]. Therefore, saliva and feces from 81 individuals were examined for the presence of H. pylori -specific DNA by simple and nested PCR.…”

“…These differences should have an impact on the efficiency of the amplification and could cause a failure in the amplification of positive samples. This issue is profound for the housekeeping gene glmM , which was used to confirm qPCR results[ 34 ], where the detection rate was only about half of that in the 16S rRNA-positive samples[ 35 - 37 ]. In another two NPCR assays, specificity was assessed through an experiment[ 31 , 38 ] on the Helicobacter -free stool samples and the products targeted to the 16S rRNA gene were sequenced.…”