Lead Sponsor

Children's Hospital of Fudan University

Age

1 - 18 years

Sex

ALL

Healthy Volunteers

Yes

•patients:
•1. Pediatric active Crohn's disease ( CD) patients who were newly diagnosed at the Children's Hospital of Fudan University from October 2020 to Sep 2022，CD was diagnosed according to the Porto criteria and based on a combination of history, physical and laboratory examination, endoscopy with histology, and imaging of the small bowel (capsule endoscopy or magnetic resonance imaging or enhanced computerized tomography).
•2. SES-CD\>4 and PCDAI \>10 at initial
•3. For the patients whose fecal will be analyzed shouldn't take antibiotics or probiotics within the 1.5 months prior to the study and during the treatment.
•healthy controls:
•1. free medical history
•2. had not taken antibiotics or probiotics within the 1.5 months prior to donate their fecal

•1. patients who had gene mutation or combined with other intestinal diseases such as tuberculosis or EB infection
•2. for patients in the EEN group who could not finish the daily prescribed volume of formula for any reason; for the patients in the IFX group who could not finish the first 4 times IFX injection for any reason.
•3. patients who were administered EEN, corticosteroids, immunosuppressive drugs, or biological agents prior to the study;
•4. patients who could not attend consecutive follow-up sessions;