Nutritional Intervention for Constipation Symptoms in Patients With Parkinson's Disease

Inclusion Criteria: * Adults with a previous diagnosis of Parkinson's disease * On a stable dose of levodopa for at least 3 months * Diagnosis of Functional Constipation by the Rome IV protocol Exclusion Criteria: * Diagnosis of atypical or secondary parkinsonism * Hoehn and Yahr stage greater than 2 * Presence of severe neurological or psychiatric disorders that impair the ability to participate in study procedures * Previous diagnosis of dementia * Presence of comorbidities such as active cancer, chronic obstructive pulmonary disease (COPD), heart failure, and/or chronic kidney disease * History of gastrointestinal cancers, inflammatory bowel diseases, or surgeries involving the gastrointestinal tract * Constipation secondary to clinical conditions such as hypothyroidism or diabetes mellitus * Use of opioids * Use of probiotics or antibiotics in the past 8 weeks * Continuous use of laxatives in the past 8 weeks * Presence of severe dysphagia according to the Functional Oral Intake Scale (FOIS) * Individuals receiving enteral or parenteral nutrition * Individuals under nutritional follow-up in the past 3 months