Site-stratified global oral Helicobacter pylori prevalence: an updated meta-analysis of dental plaque and saliva studies (1989–2026)

Background The oral cavity is a proposed extra-gastric reservoir of Helicobacter pylori, but site-stratified oral prevalence has not been updated since the 2025 dental-plaque synthesis of Anand et al., and 2024–2026 evidence remains unincorporated.Materials and methods We pooled oral H. pylori prevalence by site from 53 site-observations (49 unique study cohorts; 6,247 participants; 24 countries; 1989–2026): 33 plaque site-observations from Anand et al. (2025) plus 20 site-observations from our independent update, each verified at the abstract or full-text level. Random-effects (DerSimonian–Laird, logit) pooling with prediction intervals, subgroup, meta-regression and Egger analyses was used.Results Pooled dental-plaque prevalence was 50.2% (95% CI 43.4–57.0%; I2 = 92.2%; 39 studies) versus 32.4% (95% CI 21.2–45.9%; I2 = 97.2%; 10 studies) in saliva; caries, oral-mixed, tongue data were too sparse to pool. Plaque prevalence was numerically higher than saliva (ratio 1.55; 95% CI 0.82–2.93). PCR (45.3%) exceeded culture (39.7%); regional prevalence ranged from 31.4% (Western Pacific) to 63.0% (South-East Asia).Conclusions Dental plaque is the dominant oral H. pylori reservoir (pooled prevalence > 50%), suggesting that plaque-targeted decontamination merits evaluation as an adjunct to gastric eradication rather than being an established indication; extreme heterogeneity warrants confirmation in harmonised multi-site studies.