Background:

The key factors for success are the maintenance of intragastric pH > 6 and the drug resistance to antibiotics. Proton pump inhibitor (PPI)-based high-dose dual therapy is a novel anti-Helicobacter pylori (H. pylori) treatment. According to the investigators' previous study, the Esomeprazole-based high-dose dual therapy can achieve a higher eradication rate than standard triple therapy. The main reason for the high eradication rate was the use of high-dose esomeprazole which maintained 24-hour high intra-gastric pH. Another important reason was that investigators used only one antibiotic (Amoxicillin) with very low antibiotic resistance rates (0-2%). As compared to quadruple concomitant therapy which uses 3 antibiotics (clarithromycin, amoxicillin, and metronidazole), concomitant therapy could induce drug resistance which could affect public health issues.

Vonoprazan is a new gastric acid suppression agent, classified as a potassium-competitive acid blocker (PCAB). Its acid inhibition efficacy is superior to that of PPI. It has been evidenced that 7-day vonoprazan-based triple therapy achieved a higher eradication rate than 7-day PPI-based triple therapy in the first-line treatment of H. pylori infection but vonoprazan-based high-dose dual therapy can achieve a higher eradication rate than PPI-based thigh-dose dual therapy remains unclear.

Aims: (1) To test whether the efficacies of 14-day PCAB-based high-dose dual therapy can achieve a higher eradication rate than 14-day PPI-based high-dose dual therapy in the first-line treatment of H. pylori infection, (2) to examine the impacts of antibiotic resistance of H. pylori on the eradication efficacies of these two high-dose dual anti- H. pylori treatments.

Methods: The investigators will recruit 300 adult participants with H. pylori infection from Kaohsiung Chang Gung Memorial Hospital. Using a computer-generated randomized sequence, the investigators randomly allocated 150 patients to either 14-day high-dose dual therapy (vonoprazan 20 mg bid, and amoxicillin 750mg qid. for 14 days) or 150 patients (Esomeprezole 40 mg tid, and amoxicillin 750mg qid. for 14 days). Participants are asked to return in the second week to assess drug compliance and adverse events. Post-treatment H. pylori status is assessed by a 13C-urea breath test at week 8. Additionally, antibiotic susceptibility of H. pylori will be examined. Finally, the rates of eradication, adverse events and compliance will be compared between two groups by chi-square test, and the host and bacterial factors influencing each efficacy of the regimen are assessed by multivariate analysis.

Expected results: The acid inhibition efficacy of PCAB is superior to that of PPI. The investigators expect the PCAB-based high-dose dual therapy can achieve a better H. pylori eradication rate the PPA-based high-dose dual therapy. Minor adverse effects can be expected in each group of participants.

Inclusion Criteria:

1. At least 20 years of age, with endoscopically proven peptic ulcer diseases or gastritis are prospectively recruited for this pilot study

Exclusion Criteria:

1. Previous H. pylori-eradication therapy,
2. Ingestion of antibiotics, bismuth, or PPIs within the prior 4 weeks,
3. Patients with an allergic history to the medications used,
4. Patients with previous gastric surgery,
5. The coexistence of serious concomitant illness (for example, decompensated liver cirrhosis, uremia),
6. Pregnant women.

There are no plans to share individual participant data (IPD) from this study. The data include sensitive information that may compromise participant privacy, even if de-identified. Ethical considerations and privacy regulations prevent data sharing.