This study is intended to be a prospective observational cohort study. The incidence of gastric cancer and progression of gastric precancerous lesions will be compared between groups through prospective follow-up of a population with baseline negative gastric endoscopy, harboring high-risk Hp SNP subtypes and non-high-risk subtypes.

Primary study objective: to assess the difference in the incidence of gastric cancer between carriers of high-risk SNP subtypes of H. pylori and the non-high-risk population during the follow-up period.

Secondary research objectives: 1. To observe and compare the cumulative incidence and progression of gastric precancerous lesions (e.g., atrophic gastritis, intestinal metaplasia, etc.) in each population group during the follow-up period.2. To explore the interaction of high-risk SNPs on the risk of gastric cancer in the context of different age, gender or other risk factors (e.g. diet, smoking, alcohol abuse, family history, etc.).

Inclusion Criteria :

1. Age ≥ 40 years, gender is not limited.
2. Able and willing to provide informed consent and willing to undergo baseline and follow-up examinations.

Exclusion Criteria:

1. A history of diagnosed gastric cancer or other malignant tumors of the digestive tract.
2. Comorbid severe underlying conditions (e.g., severe cardiopulmonary insufficiency, liver or renal failure, etc.) that are likely to result in a short life expectancy or render long-term follow-up impractical.
3. Severe mental illness or incapacity to participate in the study due to lack of civil behavior.
4. Pregnant or breastfeeding women.
5. Other conditions that the investigator deems inappropriate for participation in the study.

Subjects were recruited from communities in Tongling, Anhui Province.