Constipation is a common complication and non-motor symptom of Parkinson's disease (PD) and affects up to 80% of people with PD. It is in fact within the non-motor symptoms that nutrition and dietetic intervention could have the greatest impact. Research suggests that increasing the amount of fibre in the diet could help to alleviate the effects of constipation. Inulin is a type of fibre widely found in a variety of vegetables, and recent studies have shown that inulin can improve constipation in people with PD. With the assistance of a food company, the investigators have developed a functional drink, enriched with chicory inulin and other key nutrients, including B-vitamins and vitamin D (which are suggested within the literature to be beneficial in PD). Therefore, the investigators plan to conduct a 12-week feasibility study to test the effect of this novel functional drink on gut health outcomes, nutritional status, and overall quality of life in people living with PD.