(1) The main purpose

To explore the predictive value of human microbiome and its metabolome for adverse prognosis in patients with acute ischemic stroke (AIS).

(2) Secondary purposes

1. To explore the characteristics of cross-regional disturbance of human microbiome in stroke patients;
2. To investigate the characteristics and rules of bacterial flora changes before and after recurrent apoplexy;
3. Markers closely related to AIS prognosis and cognitive emotional complications were excavated by metagenomic, metabolic, peptide and imaging groups.
4. To explore the relationship between serum markers of ultra early stage and prognosis.

This is a multicenter, prospective clinical cohort study. In this study, 2000 patients with AIS were continuously enrolled in a multicenter study, and neurological function scores (including NIHSS, mRS And ADL scores) were evaluated during and after hospitalization (3 months, 6 months, 12 months) by outpatient/telephone follow-up, and recurrent stroke and other cardiovascular and cerebrovascular events were recorded. Besides, periodontal swabs, urine, feces and blood samples were collected at multiple time points (Residual blood after the first clinical examination was collected for patients with very early stage, and blood, urine, feces and periodontal swabs were collected the next day after admission, before discharge, 3 months and 6 months after admission. Since the collection time of fecal specimens is difficult to control, only two specimens should be collected 48 hours apart during hospitalization. The first specimen should be collected as early as possible, and the time of specimen separation should be recorded.

Baseline data collection and discharge neurological function score were completed for the enrolled AIS patients before discharge, and the final diagnosis, stroke etiology classification, lifestyle survey (1 year ago), and relevant examination and treatment during hospitalization were recorded. Neurological function score, lifestyle survey, new cardiovascular and cerebrovascular events and biological specimen collection (blood, urine, feces, periodontal swab) were recorded during outpatient visits 3 months and 6 months after admission. Telephone follow-up was conducted 12 months after admission, mRS Score, ADL score and new cardiovascular and cerebrovascular events were recorded.

For the patients (750 cases) who met the criteria for inclusion in the cognitive emotion subcohort, outpatient emotional and cognitive psychological assessment was also required before discharge, 3 months and 6 months after admission on the basis of the AIS cohort.

For the subcohort with recurrence within 1 year, only data collection during hospitalization (baseline hospitalization data) and biological specimen collection during hospitalization (residual blood after the first laboratory examination was retained for patients in the very early stage, and blood, urine, feces, and periodontal swabs were collected the next day after admission and before discharge. As the time of fecal sample collection is difficult to control, it only needs to be 48 hours between hospitalization), and no follow-up will be conducted after discharge.

In addition, 500 patients without stroke were recruited as healthy control group according to the prescribed inclusion criteria.

No randomization or any study protocol-driven treatment will be administered or provided to the subject during the study. If clinically applicable, treatment decisions and treatment options are made at the discretion of the treating physician.

Inclusion Criteria:

• Meet the diagnostic criteria for AIS or TIA
• Age 18-80 years old
• Within 7 days of the onset of stroke
• Sign informed consent, provide relevant medical history and biological specimens
• Have lived in the local city for the last three years

Exclusion Criteria:

• Patients with recurrent stroke within the past year when first enrolled
• mRS > 2 points before stroke onset
• malignant tumor
• Liver and kidney dysfunction (alanine aminotransferase or aspartate aminotransferase >2 times the upper limit of normal, creatinine > 1.5 times the upper limit of normal)
• History of drug abuse and chemical poisoning (e.g. pesticide poisoning)
• In the acute stage of stroke (within 7 days from the onset of stroke) stool specimens could not be collected

Patients with ischemic stroke