Inclusion Criteria:  aged between 18 and 75 years old; H. pylori infection confirmed by any two positive outcomes of rapid urease test (RUT), 13C-urea breath test (UBT) or histopathology.  Exclusion Criteria:  previous therapy for H. pylori; with significant underlying disease (e.g. decompensated liver cirrhosis, renal failure or malignant tumors) that may interfere the study; history of gastric surgery, pregnancy or lactation; the use of PPI or antibiotics during the 4 weeks prior to enrolment; previous history of allergic reactions to any of the medications used in this protocol; unable to use smartphone and wechat unwilling or incapable to provide informed consents.