Detection of Helicobacter pylori in dental plaque among children with gastrointestinal disorders in a hospital-based cross-sectional study

Helicobacter pylori is responsible for gastritis and peptic ulcers, as well as gastric cancer. This bacterium can also be isolated from dental plaque, suggesting that the oral cavity may serve as a reservoir, contributing to reinfection after systemic antibiotic therapy. The present study was conducted to determine the presence of H. pylori and associated virulence genes in dental plaque from children with gastrointestinal disorders using PCR, and to investigate the relationship between the infection and dental caries experience (DMFT/dmft), tooth-brushing frequency, and dental visit frequency. In this cross-sectional study, 100 children with gastrointestinal disorders who were referred to Mofid Children’s Hospital in Tehran between 21 March 2023 and 19 March 2024 were included. A questionnaire was administered to collect data on gender, lifestyle, dental visit frequency, socio-economic status, and toothbrushing frequency. Oral and clinical examinations were performed before dental plaque samples were collected from the first molars or central teeth. During endoscopy, gastric biopsy specimens were obtained. The presence of gastric H. pylori was evaluated histopathologically in endoscopic biopsy specimens. Furthermore, dental plaque samples were analyzed for the presence of the 23 S rRNA , cagA , and sabA genes by polymerase chain reaction (PCR). H. pylori was detected in 54% of biopsy and 41% of dental plaque samples, respectively. All plaque-positive children were also biopsy-positive, although 13 biopsy-positive children were plaque-negative. H. pylori was not significantly associated with gender, age, parental education, or food consumption. Children who never brushed their teeth and those who visited the dentist only when they had a problem had higher odds of plaque H. pylori than those who brushed at least once daily and those with regular dental visits, respectively. Decayed teeth were more numerous in plaque-positive children. cagA was detected in 4.9% of plaque-positive samples, while no sample harbored the sabA gene. The results suggest that the oral cavity may serve as a potential reservoir for H. pylori infection in children and may be associated with dental caries, highlighting the importance of regular tooth brushing, routine dental visits, and timely treatment of dental caries in the management of H. pylori -related oral and gastric health.