Efficacy and Safety of Fecal Microbiota Transplantation in the Treatment of Parkinson's Disease With Constipation

Inclusion Criteria: * Between 18-75 years of age * Signed informed consent form * Clinical diagnosis of Parkinson's disease (according to 2016 edition of Chinese Parkinson's disease diagnostic criteria) * Parkinson's disease duration of 1 year or more * Hoehn \& Yahr stage 1-4 (including) * Patients have following 2 or more symptoms, which appear for at least 6 months and exist in recent 3 months: A. at least 25% of defecation feel strenuous; B. At least 25% of defecation was not massive or hard; C. at least 25% of defecation had incomplete feeling; D. at least 25% of defecation had anorectal obstruction; E. at least 25% of defecation needed manual assistance; F. defecation less than 3 times a week, with or without abdominal pain * Patients are taking oral L-dopa (with or without Benserazide, carbidopa, and O-methyltransferase inhibitors) at least 4 weeks, and be able to tolerate a steady dose of dopamine agonists, monoamine oxidase B inhibitors, anticholinergics, and / or adamantine. * Patients are taking stable dosage of anti-PD drugs, antidepressant drugs and antipsychotics for more than 1 month. * Be able to tolerate the FMT infusion method such as endoscopy, colonoscopy, capsule, nasoduodenal tube insertion, etc. * Be able to receive follow-up visit, follow-up examination and specimen collection on time Exclusion Criteria: * Patients with Parkinson's syndrome and Parkinsonism plus syndrome * History of cerebrovascular accident, brain injury, epilepsy and other brain injury * The "opening" stage was Hoehn \& Yahr 5 * Patient received neurosurgical intervention or stereotactic brain surgery for Parkinson's disease * Patients with organic lesions of digestive tract * Patients had major abdominal surgery * History of infectious diarrhea and took antibiotics in recent 2 weeks * Patients infected with Clostridium difficile and other pathogens * Patients with HIV or compromised immune system (such as congenital immunodeficiency or currently taking immunosuppressive drugs) * Patients with uncontrollable basic diseases of digestive system * Patients could not fully understand and sign the informed consent form * Patients who were not considered suitable for inclusion in the study