Active Helicobacter pylori Infection and Oral Mucosal Lesions, Oral Symptoms, and Gingival Bleeding in Adults: A Retrospective Cross-Sectional Study with Tooth-Level Analysis

The relationship between active Helicobacter pylori infection and clinical oral findings remains uncertain. This study compared oral mucosal lesions, oral symptoms and gingival bleeding between adults with and without active infection.This retrospective cross-sectional study included 61 adults examined between March and September 2025 and selected nonconsecutively according to their willingness to participate (83 eligible patients approached; 22 declined). Participants referred for non-invasive H. pylori testing were classified as infected (n = 29) or test-negative (n = 32) by urea breath or monoclonal stool antigen testing. Recorded oral examinations included gingival screening of 318 index teeth and 1272 sites. Firth penalized logistic regression evaluated mucosal lesions; mixed models and generalized estimating equations addressed clustered gingival outcomes. At least one mucosal lesion was present in 55.2% of infected and 21.9% of test-negative participants (difference 33.3 percentage points, 95% confidence interval [CI] 8.9–53.0; p = 0.007). The adjusted odds ratio was 5.68 (95% CI 1.67–22.84; p = 0.005; 4.61 after shrinkage for optimism). Oral burning was reported by 31.0% versus 3.1% (9 versus 1 participant; p = 0.004), whereas halitosis, dysgeusia and xerostomia did not differ significantly. The adjusted site-level odds ratio for bleeding on probing was 1.93 (95% CI 1.15–3.25) and was attenuated after exclusion of current smokers (1.55; 95% CI 0.91–2.67). Active H. pylori infection was associated with the presence of oral mucosal lesions in this small sample with a test-negative comparator group; the associations with oral burning and gingival bleeding rested on few events or were sensitive to smoking status and should be regarded as hypothesis-generating. The cross-sectional design cannot establish causation, and larger longitudinal studies with confirmed infection status are needed.