Molecular detection of Helicobacter pylori in saliva of Sri Lankan adults with periodontitis, gastritis or both conditions

Periodontitis is an immuno-inflammatory disease affecting the tooth-supporting structures, primarily caused by dysbiosis of the oral microbiome. The involvement of one of the gastric pathogens, Helicobacter pylori, has been reported among individuals with periodontitis. However, the evidence regarding the association between oral H. pylori, periodontitis, and gastritis remains inconsistent and has not been investigated in Sri Lanka. Therefore, this study aimed to detect the oral H. pylori in a cohort of Sri Lankan adults and to evaluate its association with periodontitis and gastritis. This cross-sectional study recruited 214 adults from two tertiary care institutes in Sri Lanka. Participants were categorized into four groups: (A) periodontitis only (n = 60), (B) gastritis only (n = 51), (C) both periodontitis and gastritis (n = 48), and (D) healthy controls without periodontitis or gastritis (n = 55). Unstimulated saliva samples were collected, DNA was extracted, and H. pylori was detected using PCR targeting the 16S rRNA gene. Positive samples were confirmed by ureA gene amplification. Detection rates were compared using Fisher’s exact test with Holm correction for multiple comparisons (p < 0.05). H. pylori was detected in 44 of 214 participants (20.6%; 95% CI 15.4–26.5%): periodontitis only 20.0%, gastritis only 21.6%, both conditions 31.3%, and controls 10.9%. The highest detection rate was observed in individuals with both periodontitis and gastritis (31.3%; OR 3.71, 95% CI 1.31–10.55). Although this difference did not reach statistical significance after Holm correction (adjusted p = 0.084), it represents a biologically meaningful trend warranting further investigation with larger sample sizes. No significant associations were found with age or sex (p > 0.05). H. pylori DNA is detectable in the saliva of Sri Lankan adults, with the highest detection rate observed in individuals with both periodontitis and gastritis (31.3%). This clinically relevant trend suggests that the inflamed periodontium may provide a favorable niche for the pathogen, although larger studies are needed to confirm statistical significance. This study represents the first investigation in Sri Lanka to identify the oral cavity as a potential extragastric niche for H. pylori using salivary detection. However, PCR-based detection cannot distinguish viable colonization from transient contamination. Longitudinal studies with culture-based methods and viability testing are required to clarify whether the oral cavity serves as an active reservoir for H. pylori transmission and reinfection.