BACKGROUND: Helicobacter pylori (H. pylori) initially enters the human body through the mouth. The correlation between oral health and H. pylori infection status remains a topic of debate in the scientific literature. To elucidate the relationships between H. pylori infection and oral hygiene status and habits, we performed a cross-sectional study among dyspeptic patients. METHODS: Data were collected from 362 subjects with dyspepsia symptoms who underwent the 13C-urea breath test (13C-UBT) and the H. pylori antigen test (HPS) to test for gastric and oral H. pylori infections between May and August 2023 at The Second Affiliated Hospital of Xi'an Jiaotong University. The participants completed questionnaires on sociodemographic characteristics, medical history, dyspepsia symptoms, oral hygiene status, and oral hygiene practices. In addition, the participants underwent oral exams involving the simplified oral hygiene index (OHI-S), the Debris index (DI-S), the simplified calculus index (CI-S), and the decayed, missing, and filled teeth (DMFT) score. RESULTS: Oral H. pylori infection status was not associated with sex, body mass index (BMI), education, oral hygiene habits, place of residence, or income. Considering sex and BMI, being over 60 years of age significantly increased the risk of developing oral H. pylori infection (OR = 5.51, 95% CI: 1.56-19.46, P = .0081), whereas a lack of history of antibiotic use was identified as a protective factor (OR = 0.45, 95% CI: 0.26-0.77, P = .0036). Additionally, DMFT >
4 (OR = 2.54, 95% CI: 1.15-5.61, P = .0210), 0.67 <
OHI-S ≤ 1.33 (OR = 1.98, 95% CI: 1.09-3.59, P = .0246), and 0.33<
DI≤0.67 (OR = 2.00, 95% CI: 1.11-3.62, P = .0215) were identified as independent risk factors for oral H. pylori infection. CONCLUSION: The results of our research indicate a relationship between oral health and oral H. pylori infection, suggesting that poor oral hygiene may be associated with an increased risk of oral H. pylori colonization.