Helicobacter pylori (H. pylori), which infects about 50% of the global population, has been recognized as a main risk factor of multiple gastric pathologies, especially non-cardiac gastric cancer. Strongly evidence supports that H. pylori eradication is an effective approach to reduce the incidence of those pathologies.

Inclusion Criteria:

• Consecutive patients who are 18-70 years old with persistent H. pylori infection after first or second line treatment attempts.

Exclusion Criteria:

• Enable to undergo upper endoscopy;
• Patients with gastrectomy, acute GI bleeding and advanced gastric cancer;
• Known or suspected allergy to study medications;
• Taking bismuth and antibiotics in the previous four weeks, or taking proton pump inhibitor and H2-receptor blockers in the previous two weeks;
• Currently pregnant or lactating
• Inability to provide informed consent and other situations that could interfere with the examination or therapeutic protocol.