Inclusion Criteria:  Clinical diagnosis of normal coronary artery, chronic coronary syndrome or acute coronary syndrome by coronary angiography and clinical symptoms 18-45 years old  Exclusion Criteria:  Patients with gastrointestinal diseases, recent 3 months of diarrhea, malignant tumors, autoimmune diseases and infectious diseases Patients with renal insufficiency (severe kidney disease creatinine > 267 mol/L) Patients with gastrointestinal surgery history within 1 year Patients with antibiotic use for more than 3 days within 3 months