Clinical Research Directory

Inclusion Criteria: 1. Meet the diagnostic criteria of AIS according to the Chinese Guidelines for the Diagnosis and Treatment of Acute Ischemic Stroke 2018 2. Aged 18 to 75 years old 3. Stroke within 7 days of onset 4. Sign informed consent, provide relevant medical history information and provide biological specimens Exclusion Criteria: 1. Severe impairment of consciousness (awareness score of NIHSS\>1) 2. History of stroke within 12 months 3. Severe systemic disease including malignancy 4. ALT or AST\> 2 times the upper limit of normal or severe liver disease 5. creatinine \> 1.5 times the upper limit of normal or severe kidney disease 6. History of long-term drinking, drug use, and chemical poisoning (e.g., pesticide poisoning); Note: Long-term alcohol consumption, usually more than 5 years, over 40 g/day of alcohol for men and 20 g/day for women, or a history of heavy alcohol consumption within 2 weeks, over 80 g/day of alcohol 7. History of intestinal tumors, irritable bowel syndrome or inflammatory bowel disease or confirmed in the hospital 8. Unable to collect a stool specimen within 4 days of admission 9. Assessed to be unsuitable for participation in this study by the investigator