Prebiotics and SCFA Alleviate Parkinson’s-Related Constipation: Results from a Randomized Controlled Trial

Constipation is a prevalent and clinically significant non-motor symptom in Parkinson’s disease (PD), affecting up to 90% of patients and often preceding motor dysfunction by several years. Imbalance in the gut microbiota and reduced short-chain fatty acid (SCFA) production potentially contribute to PD pathogenesis and symptom onset. This study aimed to determine whether supplementation with SCFAs, the prebiotic 2-fucosyllactose (2-FL), or their combination alleviates constipation and improves the quality of life of individuals with PD. In a double-blind, randomized, parallel-group clinical trial, 72 patients with PD were assigned to either SCFA, 2-FL, or combined supplementation groups for 6 months. Constipation and quality of life were assessed using the Cleveland Clinic Constipation Score, Bristol Stool Scale, and Patient Assessment of Constipation–Quality of Life, alongside routine neurological evaluation and physical activity questionnaires. 2-FL and combined supplementation significantly reduced constipation severity after 6 months, with the combination yielding the most pronounced and sustained benefits concerning stool consistency, defecation frequency, and patient-reported outcomes. Physical activity remained unchanged and did not affect constipation-related outcomes. Combined prebiotic and SCFA supplementation effectively alleviate constipation symptoms in patients with PD and improves patient quality of life. Future research should assess the long-term implications and potential disease-modifying effects. The study was retrospectively registered with the German Clinical Trials Register (DRKS) under the identifier DRKS00027061 on 19 November 2021 ( https://drks.de/search/en/trial/DRKS00027061/details ). Many people with Parkinson’s disease experience constipation, which can be distressing and greatly affect daily life. Constipation may appear years before movement problems and is thought to be linked to changes in gut bacteria and reduced production of beneficial substances called short-chain fatty acids. In this clinical study, we investigated whether dietary supplementation with short-chain fatty acids, the prebiotic 2-fucosyllactose, or a combination of both could improve constipation in people with Parkinson’s disease, and 72 participants received one of these supplements for 6 months. We found that supplementation with 2-fucosyllactose improved constipation symptoms, while the combination of 2-fucosyllactose and short-chain fatty acids led to the greatest and most consistent improvements, with participants reporting better stool consistency, fewer problematic bowel movements, and an improved constipation-related quality of life. Physical activity levels did not change during the study, indicating that the observed benefits were likely related to the supplements themselves. These findings suggest that targeting the gut using specific dietary supplements may offer a safe and effective way to relieve constipation in people with Parkinson’s disease, although further studies are needed to evaluate the long-term safety of these supplements, the sustainability of symptom relief, the long-term benefits, and possible effects on disease progression.