Parkinson DiseaseKIMNCT05469997
Ketogenic Diet Interventions in Parkinson's Disease: Safeguarding the Gut Microbiome
A study testing Mediterranean-Ketogenic Diet and Mediterranean diet supplemented with medium-chain triglyceride oil in people with Parkinson Disease, run by University of British Columbia at 1 site in Canada.
Trial summary
Parkinson's Disease (PD) is the second most common neurodegenerative disorder with common gut-related symptoms, which are attributed to alterations in the gut microbiome - the collection of microorganisms that live within the gut. Read more about this study
- Who is it for?
- Ages 45 to 85 years
- Conditions the study is for
- Parkinson Disease
- What is being tested?
- Mediterranean-Ketogenic Diet and Mediterranean diet supplemented with medium-chain triglyceride oil
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 52 participants
- Where
- 1 siteCanada
- Study dates
- 1 Mar 2023to 30 Oct 2024
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 45 to 85 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Age between 40-85 years
- PD diagnosis based on Movement Disorder Society (MDS) criteria [52]
- Hoehn \& Yahr score of 1 to 3
- On stable dopaminergic medication for at least one month
Who cannot join
- Atypical parkinsonism
- Medical or psychiatric conditions that would prevent full participation in the nutrition intervention
- Significant dysphagia
- Diabetes on insulin
- Anti-coagulation on warfarin
- Inflammatory bowel disease
Show all 12Show fewer
- Dementia defined by Montreal Cognitive Assessment (MoCA) Scores of less than 21
- Inability to fill in electronic questionnaires or understand study instructions
- Use of immunomodulatory agents
- Probiotic use in the last 4 weeks (except for dietary sources such as yoghurt, kefir etc.), or antibiotic use in the last 3 months prior to the trial
- Use of MCT oil or on ketogenic diet in last 8 weeks prior to the trial
- Allergic to MCT oil, coconut oil, or coconut
Trial locations and contacts
1 site in 1 country.
Canada1 site
Djawad Mowafaghian Centre for Brain Health
Vancouver, British Columbia, V6T 1Z3
About this study
Parkinson's Disease (PD) is the second most common neurodegenerative disorder with common gut-related symptoms, which are attributed to alterations in the gut microbiome - the collection of microorganisms that live within the gut. Classical ketogenic diets (KD) have shown to be beneficial in PD and non-PD populations but are associated with alterations in the gut microbiome that are characteristic of a perturbed system. This study aims to investigate the safety of modified Mediterranean-ketogenic interventions that are thought to be safer alternatives to the classical KD, as it relates to the gut microbiome health in patients with PD. We hypothesize that the modified Mediterranean-ketogenic interventions will not be associated with any significant perturbation of the gut microbiome in PD patients.
Read the detailed description
Background:
Parkinson's disease (PD), the second most common and the most rapidly growing neurodegenerative disease worldwide [1,2]. Gut-related symptoms are common and often the initial symptoms, suggesting a possible intestinal origin of PD [4]. Over a dozen studies have demonstrated gut dysbiosis in PD with reduced diversity, increased pro-inflammatory capacity, and decreased Short-Chain Fatty Acids (SCFA) production as key characteristics [5-10] and persistently increased relative abundance of Akkermansia [5-17].
Emerging evidence suggests that both ketogenic [18-23] and Mediterranean diets [24-30] have beneficial and likely complementary effects in PD. Mediterranean diets (MeDi) are primarily but not exclusively plant-based [24]. Their promotion of high fiber content intake promotes the production of SCFA and are associated with improved gut microbiome health [25]. Ketogenic diets (KD) are high in fat, adequate in protein and very low in carbohydrates [31]. KD can provide ketone bodies (KB) [32] as an alternative fuel source to glucose, the utilization of which is perturbed in the PD brain [33]. Another method for inducing the state of ketosis is by consumption of ketogenic medium-chain triglycerides (MCTs) [43]. MCTs are converted to KBs, which can readily cross the blood-brain barrier and be used as an energy source [43]. Pilot trials in PD report improved Unified Parkinson's Disease Rating Scale (UPDRS) scores [20], cognitive performance [21] and non-motor symptoms [22] with KD interventions [23].
Several studies of classical KDs in non-PD populations have observed significant alterations in the gut microbiome, including an increase in Akkermansia [47] and a decrease in fecal SCFA levels [50].
By combining the principles of MeDi with ketogenic interventions, we hope to leverage the gut-health promoting aspects of the former with bioenergetics benefits of the latter, in a safe manner. To the best of our knowledge, no clinical trials have been performed into combined ketogenic and Medi-stye dietary interventions in PD yet.
Design:
A proof of concept, random order, cross-over study in participants with PD examining two 8-week interventions: (1) the Mediterranean ketogenic diet (MeDi-KD) and (2) the Mediterranean diet supplemented with medium-chain triglycerides (MeDi-MCT), separated by an 8-week washout period.
Hypothesis:
- Neither the MeDi-MCT nor the MeDi-KD (pre-post comparison) will be significantly associated with measures of gut microbiome dysbiosis such as increased gut inflammation, impaired gut-barrier integrity, and reduced SCFA content.
- Retention rates for both diets will be at least 75%.
- Conditions
- Parkinson Disease
- Being tested
- Mediterranean-Ketogenic Diet, Mediterranean diet supplemented with medium-chain triglyceride oil
- Keywords
- Parkinson's Disease, Gut Microbiome, Ketogenic Diet, Mediterranean Diet, Medium-Chain Triglyceride, Life-style Interventions
- Medical subject headings
- Parkinson Disease
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Mediterranean-Ketogenic DietBehavioural
Also called MeDi-KD
In the MeDi-KD group, the participants will adhere to a modified Mediterranean-ketogenic diet. The ketogenic component of the diet will require limiting the intake of carbohydrates to about 10% of all calories consumed in a day, while obtaining most of the energy from healthy fats, mostly from plant-based sources (~70-75% of your daily caloric intake) and lean proteins (~15-20% of your daily caloric intake). The ketogenic ratio (the ratio of fat to carbohydrates) will be gradually increased during the first week from 1:1 to 3:1. The Mediterranean component of the diet will encourage the participants to consume more green leafy vegetables, nuts, and olive oil, while limiting the consumption of processed or fried food, red meat, full-fat dairy, and sweets.
Mediterranean diet supplemented with medium-chain triglyceride oilDietary supplement
Also called MeDi-MCT
The participants will adhere to the Mediterranean diet. In addition, they will be asked to take two daily doses of medium-chain triglyceride oil (MCT oil).
The MCT oil supplement (Nutiva MCT oil, Nutiva Inc.) is approved by Health Canada (NPN: 80086912) and will be used according to its approved condition of use (i.e., source of medium-chain fatty acids which supports energy production in the body at a cellular level [ATP]). Each serving of this product provides 130 Calories from MCTs (14 g) with a C8-C10 ratio of 60:40. Nutiva MCT oil can be mixed into any beverage of choice, but cannot be used for cooking.
participants will start the intervention by taking 5 mL of MCT oil twice daily for the first day to acclimate their bodies to the supplement and gradually increase the dose to 14 g BID by the end of week 1. The participants may be asked to increase the dose to 20 mL of MCT twice daily if tolerability remains positive.
| Study group | Role | What they receive |
|---|---|---|
| MeDi(KD-MCT) | Experimental | The participants in this arm will first undergo the MeDi-KD intervention followed by the MeDi-MCT intervention, after an 8-week washout period. Receives: Behavioral: Mediterranean-Ketogenic Diet; Dietary Supplement: Mediterranean diet supplemented with medium-chain triglyceride oil |
| MeDi(MCT-KD) | Experimental | The participants in this arm will first undergo the MeDi-MCT intervention followed by the MeDi-KD intervention, after an 8-week washout period. Receives: Behavioral: Mediterranean-Ketogenic Diet; Dietary Supplement: Mediterranean diet supplemented with medium-chain triglyceride oil |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change from baseline and difference across interventions in measures of fecal and serum calprotectin, a biomarker for gut inflammation.
We will assess changes from baseline in levels of fecal and serum calprotectin, a biomarker for gut inflammation that is found at elevated levels in PD patients, before and after each 8-week intervention. We will also compare the two interventions to determine their relative safety.
Measured: Preintervention 1 (Baseline 1)/ Post-intervention 1 (Week 8)/ Pre-intervention 2 (baseline 2; Week 16)/ Post-intervention 2 (Week 24)
Changes from baseline and differences across interventions in other measures of gut health, namely short-chain fatty acid production, gut-barrier integrity, and microbial composition.
We will assess changes from baseline in the following biomarkers of gut health before and after each 8-week intervention:
Short-chain fatty acid (SCFA)/ butyrate production measured in freshly frozen fecal samples Gut microbiome compositions measure in fecal samples. Levels of zonulin, a biomarker for gut-barrier function, measured in fecal and blood serum samples.
We will track any potential adverse events.
Measured: Preintervention 1 (Baseline 1)/ Post-intervention 1 (Week 8)/ Pre-intervention 2 (baseline 2; Week 16)/ Post-intervention 2 (Week 24)
Secondary outcomes (2)
The number of participants who completed the study after successful enrollment relative to the total enrolled participants.
We will assess the retention rate of participants with respect to each intervention to determine the feasibility of the proposed dietary interventions.
Measured: Post-intervention 1 (Week 8)/Post-intervention 2 (Week 24)
Percent time spent in clinically relevant levels of ketosis ( equivalent to >0.5 mmol/L) by each participant throughout each intervention.
Adherence to the ketogenic dietary interventions will be measured using breath ketone analyzers (Ketonix). The participants will take daily measurements of their breath ketone levels and record them in their study journal.
Percent time is determined by the number of days they successfully reach clinically relevant levels of ketosis relative to the total intervention days for each intervention (i.e. 56 days).
Measured: Post-intervention 1 (Week 8)/Post-intervention 2 (Week 24)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted22 Jul 2022
- Study start1 Mar 2023
- Primary completion30 Oct 2024
- Study completion30 Oct 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (83)Papers the sponsor has linked to this study.
- Other trials for Parkinson DiseaseStudies of the same condition, open and under way.
- More trials run by University of British ColumbiaThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Supportive care
- Allocation
- Randomised
- Intervention model
- Crossover
- Model description
- This safety study consists of two 8-week interventions (MeDi-MCT and MeDi-KD) in randomized order using a cross-over design, separated by an 8-week washout period. Participants will be randomized into either the MeDi-MCT or the MeDi-KD group for the first phase of the study. After 8-weeks of intervention, they will undergo an 8-week washout period where no interventions will be applied. Subsequently, the participants will commence the second phase of the study by receiving the other study intervention for 8 weeks.
- Masking
- None (open label)
- Enrolment
- 52 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of British Columbia
- Sponsor type
- University, hospital or other
- Collaborators
- Weston Family Foundation
- Responsible party
- Principal investigator, Silke Cresswell, University of British Columbia
- Investigators
- Silke Appel-Cresswell, MD, Principal investigator, University of British Columbia
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05469997
- Sponsor's protocol ID
- H21-03747
- Acronym
- KIM
- Status last verified
- Mar 2026
- First submitted
- 15 Jun 2022
- Last updated
- 23 Mar 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Publications
GBD 2016 Parkinson's Disease Collaborators. Global, regional, and national burden of Parkinson's disease, 1990-2016: a systematic analysis for the Global Burden of Disease Study 2016. Lancet Neurol. 2018 Nov;17(11):939-953. doi: 10.1016/S1474-4422(18)30295-3. Epub 2018 Oct 1.
PubMed 30287051Dorsey ER, Sherer T, Okun MS, Bloem BR. The Emerging Evidence of the Parkinson Pandemic. J Parkinsons Dis. 2018;8(s1):S3-S8. doi: 10.3233/JPD-181474.
PubMed 30584159van der Kolk NM, de Vries NM, Kessels RPC, Joosten H, Zwinderman AH, Post B, Bloem BR. Effectiveness of home-based and remotely supervised aerobic exercise in Parkinson's disease: a double-blind, randomised controlled trial. Lancet Neurol. 2019 Nov;18(11):998-1008. doi: 10.1016/S1474-4422(19)30285-6. Epub 2019 Sep 11.
PubMed 31521532Borghammer P, Van Den Berge N. Brain-First versus Gut-First Parkinson's Disease: A Hypothesis. J Parkinsons Dis. 2019;9(s2):S281-S295. doi: 10.3233/JPD-191721.
PubMed 31498132Sampson TR, Debelius JW, Thron T, Janssen S, Shastri GG, Ilhan ZE, Challis C, Schretter CE, Rocha S, Gradinaru V, Chesselet MF, Keshavarzian A, Shannon KM, Krajmalnik-Brown R, Wittung-Stafshede P, Knight R, Mazmanian SK. Gut Microbiota Regulate Motor Deficits and Neuroinflammation in a Model of Parkinson's Disease. Cell. 2016 Dec 1;167(6):1469-1480.e12. doi: 10.1016/j.cell.2016.11.018.
PubMed 27912057Aho VTE, Houser MC, Pereira PAB, Chang J, Rudi K, Paulin L, Hertzberg V, Auvinen P, Tansey MG, Scheperjans F. Relationships of gut microbiota, short-chain fatty acids, inflammation, and the gut barrier in Parkinson's disease. Mol Neurodegener. 2021 Feb 8;16(1):6. doi: 10.1186/s13024-021-00427-6.
PubMed 33557896Hirayama M, Ohno K. Parkinson's Disease and Gut Microbiota. Ann Nutr Metab. 2021;77 Suppl 2:28-35. doi: 10.1159/000518147. Epub 2021 Sep 9.
PubMed 34500451Boertien JM, Pereira PAB, Aho VTE, Scheperjans F. Increasing Comparability and Utility of Gut Microbiome Studies in Parkinson's Disease: A Systematic Review. J Parkinsons Dis. 2019;9(s2):S297-S312. doi: 10.3233/JPD-191711.
PubMed 31498131Cirstea MS, Yu AC, Golz E, Sundvick K, Kliger D, Radisavljevic N, Foulger LH, Mackenzie M, Huan T, Finlay BB, Appel-Cresswell S. Microbiota Composition and Metabolism Are Associated With Gut Function in Parkinson's Disease. Mov Disord. 2020 Jul;35(7):1208-1217. doi: 10.1002/mds.28052. Epub 2020 May 1.
PubMed 32357258Wallen ZD, Appah M, Dean MN, Sesler CL, Factor SA, Molho E, Zabetian CP, Standaert DG, Payami H. Characterizing dysbiosis of gut microbiome in PD: evidence for overabundance of opportunistic pathogens. NPJ Parkinsons Dis. 2020 Jun 12;6:11. doi: 10.1038/s41531-020-0112-6. eCollection 2020.
PubMed 32566740Barichella M, Severgnini M, Cilia R, Cassani E, Bolliri C, Caronni S, Ferri V, Cancello R, Ceccarani C, Faierman S, Pinelli G, De Bellis G, Zecca L, Cereda E, Consolandi C, Pezzoli G. Unraveling gut microbiota in Parkinson's disease and atypical parkinsonism. Mov Disord. 2019 Mar;34(3):396-405. doi: 10.1002/mds.27581. Epub 2018 Dec 21.
PubMed 30576008Nishiwaki H, Ito M, Ishida T, Hamaguchi T, Maeda T, Kashihara K, Tsuboi Y, Ueyama J, Shimamura T, Mori H, Kurokawa K, Katsuno M, Hirayama M, Ohno K. Meta-Analysis of Gut Dysbiosis in Parkinson's Disease. Mov Disord. 2020 Sep;35(9):1626-1635. doi: 10.1002/mds.28119. Epub 2020 Jun 18.
PubMed 32557853Scheperjans F, Aho V, Pereira PA, Koskinen K, Paulin L, Pekkonen E, Haapaniemi E, Kaakkola S, Eerola-Rautio J, Pohja M, Kinnunen E, Murros K, Auvinen P. Gut microbiota are related to Parkinson's disease and clinical phenotype. Mov Disord. 2015 Mar;30(3):350-8. doi: 10.1002/mds.26069. Epub 2014 Dec 5.
PubMed 25476529Keshavarzian A, Green SJ, Engen PA, Voigt RM, Naqib A, Forsyth CB, Mutlu E, Shannon KM. Colonic bacterial composition in Parkinson's disease. Mov Disord. 2015 Sep;30(10):1351-60. doi: 10.1002/mds.26307. Epub 2015 Jul 16.
PubMed 26179554Unger MM, Spiegel J, Dillmann KU, Grundmann D, Philippeit H, Burmann J, Fassbender K, Schwiertz A, Schafer KH. Short chain fatty acids and gut microbiota differ between patients with Parkinson's disease and age-matched controls. Parkinsonism Relat Disord. 2016 Nov;32:66-72. doi: 10.1016/j.parkreldis.2016.08.019. Epub 2016 Aug 26.
PubMed 27591074
Study at a glance
From the registry record, last updated by the sponsor on 23 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Ketogenic Diet Interventions in Parkinson's Disease: Safeguarding the Gut Microbiome
- ClinicalTrials.gov ID
- NCT05469997
- Acronym / sponsor ID
- KIM / H21-03747
- Conditions
- Parkinson Disease
- Keywords
- Parkinson's Disease, Gut Microbiome, Ketogenic Diet, Mediterranean Diet, Medium-Chain Triglyceride, Life-style Interventions
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 52 participants (actual)
- Lead sponsor
- University of British ColumbiaUniversity, hospital or other
- Collaborators
- Weston Family Foundation
- Study start
- 1 Mar 2023 (actual)
- Primary completion
- 30 Oct 2024 (actual)
- Study completion
- 30 Oct 2024 (actual)
- First posted
- 22 Jul 2022 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Parkinson's Disease (PD) is the second most common neurodegenerative disorder with common gut-related symptoms, which are attributed to alterations in the gut microbiome - the collection of microorganisms that live within the gut. Classical ketogenic diets (KD) have shown to be beneficial in PD and non-PD populations but are associated with alterations in the gut microbiome that are characteristic of a perturbed system. This study aims to investigate the safety of modified Mediterranean-ketogenic interventions that are thought to be safer alternatives to the classical KD, as it relates to the gut microbiome health in patients with PD. We hypothesize that the modified Mediterranean-ketogenic interventions will not be associated with any significant perturbation of the gut microbiome in PD patients.
Detailed description
Background:
Parkinson's disease (PD), the second most common and the most rapidly growing neurodegenerative disease worldwide [1,2]. Gut-related symptoms are common and often the initial symptoms, suggesting a possible intestinal origin of PD [4]. Over a dozen studies have demonstrated gut dysbiosis in PD with reduced diversity, increased pro-inflammatory capacity, and decreased Short-Chain Fatty Acids (SCFA) production as key characteristics [5-10] and persistently increased relative abundance of Akkermansia [5-17].
Emerging evidence suggests that both ketogenic [18-23] and Mediterranean diets [24-30] have beneficial and likely complementary effects in PD. Mediterranean diets (MeDi) are primarily but not exclusively plant-based [24]. Their promotion of high fiber content intake promotes the production of SCFA and are associated with improved gut microbiome health [25]. Ketogenic diets (KD) are high in fat, adequate in protein and very low in carbohydrates [31]. KD can provide ketone bodies (KB) [32] as an alternative fuel source to glucose, the utilization of which is perturbed in the PD brain [33]. Another method for inducing the state of ketosis is by consumption of ketogenic medium-chain triglycerides (MCTs) [43]. MCTs are converted to KBs, which can readily cross the blood-brain barrier and be used as an energy source [43]. Pilot trials in PD report improved Unified Parkinson's Disease Rating Scale (UPDRS) scores [20], cognitive performance [21] and non-motor symptoms [22] with KD interventions [23].
Several studies of classical KDs in non-PD populations have observed significant alterations in the gut microbiome, including an increase in Akkermansia [47] and a decrease in fecal SCFA levels [50].
By combining the principles of MeDi with ketogenic interventions, we hope to leverage the gut-health promoting aspects of the former with bioenergetics benefits of the latter, in a safe manner. To the best of our knowledge, no clinical trials have been performed into combined ketogenic and Medi-stye dietary interventions in PD yet.
Design:
A proof of concept, random order, cross-over study in participants with PD examining two 8-week interventions: (1) the Mediterranean ketogenic diet (MeDi-KD) and (2) the Mediterranean diet supplemented with medium-chain triglycerides (MeDi-MCT), separated by an 8-week washout period.
Hypothesis:
- Neither the MeDi-MCT nor the MeDi-KD (pre-post comparison) will be significantly associated with measures of gut microbiome dysbiosis such as increased gut inflammation, impaired gut-barrier integrity, and reduced SCFA content.
- Retention rates for both diets will be at least 75%.
Study design
- Primary purpose
- Supportive care
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Number of arms
- 2
- Model description
- This safety study consists of two 8-week interventions (MeDi-MCT and MeDi-KD) in randomized order using a cross-over design, separated by an 8-week washout period. Participants will be randomized into either the MeDi-MCT or the MeDi-KD group for the first phase of the study. After 8-weeks of intervention, they will undergo an 8-week washout period where no interventions will be applied. Subsequently, the participants will commence the second phase of the study by receiving the other study intervention for 8 weeks.
| Arm | Type | Receives |
|---|---|---|
| MeDi(KD-MCT) | Experimental | Behavioral: Mediterranean-Ketogenic Diet, Dietary Supplement: Mediterranean diet supplemented with medium-chain triglyceride oilThe participants in this arm will first undergo the MeDi-KD intervention followed by the MeDi-MCT intervention, after an 8-week washout period. |
| MeDi(MCT-KD) | Experimental | Behavioral: Mediterranean-Ketogenic Diet, Dietary Supplement: Mediterranean diet supplemented with medium-chain triglyceride oilThe participants in this arm will first undergo the MeDi-MCT intervention followed by the MeDi-KD intervention, after an 8-week washout period. |
Who may qualify
- Ages
- 45 to 85 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Age between 40-85 years
- PD diagnosis based on Movement Disorder Society (MDS) criteria [52]
- Hoehn \& Yahr score of 1 to 3
- On stable dopaminergic medication for at least one month
Key exclusion criteria (12 listed)
- Atypical parkinsonism
- Medical or psychiatric conditions that would prevent full participation in the nutrition intervention
- Significant dysphagia
- Diabetes on insulin
- Anti-coagulation on warfarin
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Mediterranean-Ketogenic DietAlso: MeDi-KDIn the MeDi-KD group, the participants will adhere to a modified Mediterranean-ketogenic diet. The ketogenic component of the diet will require limiting the intake of carbohydrates to about 10% of all calories consumed in a day, while obtaining most of the energy from healthy fats, mostly from plant-based sources (~70-75% of your daily caloric intake) and lean proteins (~15-20% of your daily caloric intake). The ketogenic ratio (the ratio of fat to carbohydrates) will be gradually increased during the first week from 1:1 to 3:1. The Mediterranean component of the diet will encourage the participants to consume more green leafy vegetables, nuts, and olive oil, while limiting the consumption of processed or fried food, red meat, full-fat dairy, and sweets. | Behavioural | MeDi(KD-MCT), MeDi(MCT-KD) |
| Mediterranean diet supplemented with medium-chain triglyceride oilAlso: MeDi-MCTThe participants will adhere to the Mediterranean diet. In addition, they will be asked to take two daily doses of medium-chain triglyceride oil (MCT oil). The MCT oil supplement (Nutiva MCT oil, Nutiva Inc.) is approved by Health Canada (NPN: 80086912) and will be used according to its approved condition of use (i.e., source of medium-chain fatty acids which supports energy production in the body at a cellular level [ATP]). Each serving of this product provides 130 Calories from MCTs (14 g) with a C8-C10 ratio of 60:40. Nutiva MCT oil can be mixed into any beverage of choice, but cannot be used for cooking. participants will start the intervention by taking 5 mL of MCT oil twice daily for the first day to acclimate their bodies to the supplement and gradually increase the dose to 14 g BID by the end of week 1. The participants may be asked to increase the dose to 20 mL of MCT twice daily if tolerability remains positive. | Dietary supplement | MeDi(KD-MCT), MeDi(MCT-KD) |
Primary outcome
Change from baseline and difference across interventions in measures of fecal and serum calprotectin, a biomarker for gut inflammation.
Time frame: Preintervention 1 (Baseline 1)/ Post-intervention 1 (Week 8)/ Pre-intervention 2 (baseline 2; Week 16)/ Post-intervention 2 (Week 24)
We will assess changes from baseline in levels of fecal and serum calprotectin, a biomarker for gut inflammation that is found at elevated levels in PD patients, before and after each 8-week intervention. We will also compare the two interventions to determine their relative safety.
Changes from baseline and differences across interventions in other measures of gut health, namely short-chain fatty acid production, gut-barrier integrity, and microbial composition.
Time frame: Preintervention 1 (Baseline 1)/ Post-intervention 1 (Week 8)/ Pre-intervention 2 (baseline 2; Week 16)/ Post-intervention 2 (Week 24)
We will assess changes from baseline in the following biomarkers of gut health before and after each 8-week intervention: Short-chain fatty acid (SCFA)/ butyrate production measured in freshly frozen fecal samples Gut microbiome compositions measure in fecal samples. Levels of zonulin, a biomarker for gut-barrier function, measured in fecal and blood serum samples. We will track any potential adverse events.
2 secondary outcomes
The number of participants who completed the study after successful enrollment relative to the total enrolled participants.
Time frame: Post-intervention 1 (Week 8)/Post-intervention 2 (Week 24)
Percent time spent in clinically relevant levels of ketosis ( equivalent to >0.5 mmol/L) by each participant throughout each intervention.
Time frame: Post-intervention 1 (Week 8)/Post-intervention 2 (Week 24)
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 23 Mar 2026.
- Background: PubMed 30287051GBD 2016 Parkinson's Disease Collaborators. Global, regional, and national burden of Parkinson's disease, 1990-2016: a systematic analysis for the Global Burden of Disease Study 2016. Lancet Neurol. 2018 Nov;17(11):939-953. doi: 10.1016/S1474-4422(18)30295-3. Epub 2018 Oct 1.
- Background: PubMed 30584159Dorsey ER, Sherer T, Okun MS, Bloem BR. The Emerging Evidence of the Parkinson Pandemic. J Parkinsons Dis. 2018;8(s1):S3-S8. doi: 10.3233/JPD-181474.
- Background: PubMed 31521532van der Kolk NM, de Vries NM, Kessels RPC, Joosten H, Zwinderman AH, Post B, Bloem BR. Effectiveness of home-based and remotely supervised aerobic exercise in Parkinson's disease: a double-blind, randomised controlled trial. Lancet Neurol. 2019 Nov;18(11):998-1008. doi: 10.1016/S1474-4422(19)30285-6. Epub 2019 Sep 11.
- Background: PubMed 31498132Borghammer P, Van Den Berge N. Brain-First versus Gut-First Parkinson's Disease: A Hypothesis. J Parkinsons Dis. 2019;9(s2):S281-S295. doi: 10.3233/JPD-191721.
- Background: PubMed 27912057Sampson TR, Debelius JW, Thron T, Janssen S, Shastri GG, Ilhan ZE, Challis C, Schretter CE, Rocha S, Gradinaru V, Chesselet MF, Keshavarzian A, Shannon KM, Krajmalnik-Brown R, Wittung-Stafshede P, Knight R, Mazmanian SK. Gut Microbiota Regulate Motor Deficits and Neuroinflammation in a Model of Parkinson's Disease. Cell. 2016 Dec 1;167(6):1469-1480.e12. doi: 10.1016/j.cell.2016.11.018.
- Background: PubMed 33557896Aho VTE, Houser MC, Pereira PAB, Chang J, Rudi K, Paulin L, Hertzberg V, Auvinen P, Tansey MG, Scheperjans F. Relationships of gut microbiota, short-chain fatty acids, inflammation, and the gut barrier in Parkinson's disease. Mol Neurodegener. 2021 Feb 8;16(1):6. doi: 10.1186/s13024-021-00427-6.
- Background: PubMed 34500451Hirayama M, Ohno K. Parkinson's Disease and Gut Microbiota. Ann Nutr Metab. 2021;77 Suppl 2:28-35. doi: 10.1159/000518147. Epub 2021 Sep 9.
- Background: PubMed 31498131Boertien JM, Pereira PAB, Aho VTE, Scheperjans F. Increasing Comparability and Utility of Gut Microbiome Studies in Parkinson's Disease: A Systematic Review. J Parkinsons Dis. 2019;9(s2):S297-S312. doi: 10.3233/JPD-191711.
- Background: PubMed 32357258Cirstea MS, Yu AC, Golz E, Sundvick K, Kliger D, Radisavljevic N, Foulger LH, Mackenzie M, Huan T, Finlay BB, Appel-Cresswell S. Microbiota Composition and Metabolism Are Associated With Gut Function in Parkinson's Disease. Mov Disord. 2020 Jul;35(7):1208-1217. doi: 10.1002/mds.28052. Epub 2020 May 1.
- Background: PubMed 32566740Wallen ZD, Appah M, Dean MN, Sesler CL, Factor SA, Molho E, Zabetian CP, Standaert DG, Payami H. Characterizing dysbiosis of gut microbiome in PD: evidence for overabundance of opportunistic pathogens. NPJ Parkinsons Dis. 2020 Jun 12;6:11. doi: 10.1038/s41531-020-0112-6. eCollection 2020.
- Background: PubMed 30576008Barichella M, Severgnini M, Cilia R, Cassani E, Bolliri C, Caronni S, Ferri V, Cancello R, Ceccarani C, Faierman S, Pinelli G, De Bellis G, Zecca L, Cereda E, Consolandi C, Pezzoli G. Unraveling gut microbiota in Parkinson's disease and atypical parkinsonism. Mov Disord. 2019 Mar;34(3):396-405. doi: 10.1002/mds.27581. Epub 2018 Dec 21.
- Background: PubMed 32557853Nishiwaki H, Ito M, Ishida T, Hamaguchi T, Maeda T, Kashihara K, Tsuboi Y, Ueyama J, Shimamura T, Mori H, Kurokawa K, Katsuno M, Hirayama M, Ohno K. Meta-Analysis of Gut Dysbiosis in Parkinson's Disease. Mov Disord. 2020 Sep;35(9):1626-1635. doi: 10.1002/mds.28119. Epub 2020 Jun 18.
- Individual participant dataSharing planned: Undecided
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Silke Appel-Cresswell, MD principal investigator
University of British Columbia
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Mediterranean-Ketogenic Diet and Mediterranean diet supplemented with medium-chain triglyceride oil in people with Parkinson Disease, run by University of British Columbia at 1 site in Canada.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 12 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 23 Mar 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Canada. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change from baseline and difference across interventions in measures of fecal and serum calprotectin, a biomarker for gut inflammation. (time frame: Preintervention 1 (Baseline 1)/ Post-intervention 1 (Week 8)/ Pre-intervention 2 (baseline 2; Week 16)/ Post-intervention 2 (Week 24)). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT05469997, which also lists 83 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 23 Mar 2026.