Clinical Research Directory

Inclusion Criteria: * Pre-adolescent children with Prader Willi syndrome which were definitely diagnosed by gene testing. * Consistent with the diagnostic criteria for obesity. * Not participate in other research projects at present or three months before the research; * Agree to participate in the test and obtain the consent of their parents; voluntarily be the subjects and sign the informed consent form. Exclusion Criteria: * Losing weight in ways other than the intervention measures of this project, such as taking weight loss drugs or known drugs that cause weight change; * Use antibiotics within 1 month before the study and lasted for 3 days or more; * Use probiotics within 1 month before the study and lasted for 3 days or more; * Complicated with liver and renal insufficiency (alanine aminotransferase and serum creatinine indexes exceed 2 times the upper limit of the normal value set by the hospital); * Have gastrointestinal diseases affecting food digestion and absorption (such as severe diarrhea, constipation, severe gastrointestinal inflammation, active gastrointestinal ulcer, acute cholecystitis, etc.); severe diarrhea refers to watery stool 3 or more times a day and lasts for 3 or more days. severe constipation refers to defecation 2 or less times a week with difficulty in defecation; * Surgery was performed within 1 year before the study (except for appendicitis and hernia surgery); * Have hepatitis B, active tuberculosis, AIDS and other infectious diseases; * Those who are suffering from mental illness and are taking psychotropic drugs such as antidepressants.