Associations Among Serum and Gastric Juice Bile Acid Profile, Bile Acid-microbiota Cross-talk in Stomach and the Development of Gastric Cancer

Inclusion Criteria:

1. Age 18 to 75 years old, gender is not limited;
2. No history of antibiotic or probiotic use for 8 weeks;
3. No preoperative chemotherapy or radiation therapy prior to the examination;
4. Voluntary intravenous blood collection, gastroscopy, extraction of gastric juice and pathological biopsy.
5. Voluntary testing for H. pylori

Exclusion Criteria:

1. had undergone upper gastrointestinal and colon surgery;
2. Previous diagnosis of Malignant Tumors;
3. Presence of a disease or medication that affects bile acid metabolism, such as endocrine or autoimmune diseases;
4. Recent use of drugs that affect gastrointestinal motility;
5. Presence of contraindications to endoscopy;
6. pregnant and lactating women;
7. Those with mental disorders;
8. Refusal to sign the informed consent form.