The Gut Microbiome and Sorafenib Maintenance Therapy in FLT3-ITD Positive AML After Allo-HSCT

Inclusion Criteria: * FLT3-ITD Positive AML * Allo-HSCT Recipients Exclusion Criteria: * intolerance to sorafenib pretransplantation * Cardiac dysfunction (particularly congestive heart failure) * Hepatic abnormalities (bilirubin ≥ 3 mg/dL, aminotransferase\> 2 times the upper limit of normal) * Renal dysfunction (creatinine clearance rate \< 30 mL/min) * Any abnormality in a vital sign (e.g., heart rate, respiratory rate, or blood pressure) * Patients with any conditions not suitable for the trial (according to the investigators' decision)