Analysis of oral microbiota alterations induced by Helicobacter pylori infection and vonoprazan-amoxicillin dual therapy for Helicobacter pylori eradication.

Background: The oral cavity is considered a potential reservoir of Helicobacter pylori (H. pylori), and the imbalance of oral microbiota directly reflects the health of the host. We aimed to explore the relationship among oral microbiota, H. pylori infection, and vonoprazan-amoxicillin (VA) dual therapy for H. pylori eradication.

Methods: Helicobacter pylori-positive patients were randomized into low- or high-dose VA dual therapy (i.e., amoxicillin 1 g b.i.d. or t.i.d. and vonoprazan 20 mg b.i.d) for 7 or 10 days. H. pylori-negative patients served as normal controls. Saliva samples were collected from 41 H. pylori-positive patients and 13 H. pylori-negative patients. The oral microbiota was analyzed by 16S rRNA gene sequencing, followed by bioinformatics analysis.

Results: Helicobacter pylori-positive patients had higher richness and diversity and better evenness of oral microbiota than normal controls. Beta diversity analysis estimated by Bray-Curtis or weighted UniFrac showed distinct clustering between H. pylori-positive patients and normal controls. The number of bacterial interactions was reduced in H. pylori-positive patients compared with that in negative patients. Forty-one patients evaluated before and after successful H. pylori eradication were divided into low (L-VA) and high dose (H-VA) amoxicillin dose groups. The alpha and beta diversity of the oral microbiota between L-VA and H-VA patients exhibited no differences at the three time points (before eradication, after eradication, and at confirmation of H. pylori infection cure).

Conclusion: Helicobacter pylori infection could alter the diversity, composition, and bacterial interactions of the oral microbiota. Both L-VA and H-VA dual therapy showed minimal influence on the oral microbiota.