Ketogenic Diet Interventions in Parkinson's Disease: Safeguarding the Gut Microbiome

简要总结

详细描述

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: 1. 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. 2. Retention rates for both diets will be at least 75%.

主要结局

次要结局

• The number of participants who completed the study after successful enrollment relative to the total enrolled participants.(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.(Post-intervention 1 (Week 8)/Post-intervention 2 (Week 24))