Fecal Microbiota Transplantation Via Oral Capsule for Treating Refractory Constipation in Parkinson's Disease

Inclusion Criteria: * Aged between 40 and 80 years. * Voluntarily signed the informed consent form for participation in this study. * Diagnosed with Parkinson's disease according to the UK Brain Bank Criteria. * Either do not have or have controlled Parkinson's disease motor complications, allowing for stable use of anti-Parkinson's medication during the study period (12 weeks). * Meet the definition of refractory constipation as follows: A. On at least 1 out of 4 bowel movements, two or more of the following apply: i. Excessive straining. ii. Lumpy/hard stools (Bristol Stool Form Scale 1-2). iii. Sensation of incomplete evacuation after defecation. iv. Sensation of anorectal obstruction or blockage. v. Manual maneuvers to facilitate defecation. vi. Fewer than three spontaneous bowel movements per week. B. Rarely experience loose stools without the use of laxatives. C. Symptoms began at least 6 months prior to diagnosis and have persisted for the past 3 months. D. Constipation shows no improvement despite the use of various types of laxatives (bulk-forming, osmotic, saline, stimulant, or others) individually or in combination for at least 4 weeks. Exclusion Criteria: * Individuals with cognitive impairment scoring less than 20 on the Korean version of the Mini-Mental State Examination (K-MMSE). * Individuals who have contraindications for fecal microbiota transplantation (acute infections, immunocompromised status, or a history of food allergies). * Individuals with ile…