Inclusion Criteria:  Community population over 3 years old who signed the informed consent. at least 2 people in the family. living together for at least 10 months each year in the past 5 years except child aged below 5.  Exclusion Criteria:  PPI drugs such as esomeprazole、pantoprazole、 rabeprazole,、lansoprazole、famotidine and H2 receptor antagonists were taken within two weeks. antibiotics、bismuth agents or traditional Chinese medicine with antibacterial effect were taken within four weeks There are other factors that researchers think are not suitable for participation