Parkinson's Disease (PD) is a debilitating progressive neurodegenerative disorder, second in frequency only to Alzheimer's disease, affecting around 10 million people worldwide. PD is characterized by loss of dopaminergic cells in substantia nigra and the accumulation of Lewy bodies. There is no disease modifying treatment or cure for the disease and management strategies focus on symptomatic treatment. One of the proposed mechanisms for the dopaminergic neurons degeneration in sporadic Parkinson's disease cases is related to compromise cellular bioenergetics, resulting in excessive production of reactive oxygen species (ROS) that leads to oxidative stress. Numerous studies have identified mitochondrial dysfunction as the central pathological features of both genetic and sporadic PD. Mitochondrial dysfunction can also increase inflammation which is associated with PD and Lewy Body formation. Elevated plasma ketones have been shown to enhance energy reserves, ATP levels and the expression of many enzymes involved in multiple metabolic pathways in the mitochondria. This pilot study aims to assess the effect of an exogenous ketone supplement on functional performance in people with PD. Changes in inflammatory makers will also be assessed. Participants will ingest the exogenous ketone supplement four times per day for four weeks. Participants will undergo neurological, functional, and cognitive assessments prior to and after the four-week intervention. Dietitians will follow up with participants weekly for compliance and counseling. Diet will be assessed throughout the study using the automated self-administered 24-hour dietary recall. After the four week intervention, a two-week "washout" period will be observed before reassessing functional and cognitive performance again.

Additionally, the study would like to establish the extent to which the use of Ketone esters impact the gut microbiota. Gut microbita composition in PD has been associated with symptoms and treatment efficacy.