The missing piece of the puzzle - The key role of the dietitian in the management of Parkinson's disease.

The current paradigm for the multidisciplinary management of Parkinson's Disease (PD) does not include regular nutritional assessment despite research showing that 90 % of people living with Parkinson's (PwP) lack access to basic dietetic services. Since many non-motor symptoms such as dysphagia, constipation and orthostatic hypotension and PD complications such as weight loss and sarcopenia can be improved through dietary intervention, dietitians are a critical missing piece of the PD management puzzle. This paper serves to review the role of dietitians and medical nutrition therapy in management of PD as well as a call to action for future studies to investigate improvement of nutritional status and quality of life for all PwP.

Levodopa-induced dyskinesia: a historical review of Parkinson's disease, dopamine, and modern advancements in research and treatment.

Over the past two decades, animal models of Parkinson's disease (PD) have helped to determine the plausible underlying mechanism of levo-dihydroxyphenylalanine (L-DOPA)-induced dyskinesia following L-DOPA treatment. However, our understanding of the mechanisms related to this phenomenon remains incomplete. The purpose of this manuscript is to provide a comprehensive review of treatment protocols used for assessing the occurrence of L-DOPA-induced dyskinesia, L-DOPA absorption, distribution, drug/food interaction, and discuss current strategies and future directions. This review offers a historical perspective using L-DOPA in animal models of PD and the occurrence of L-DOPA-induced dyskinesia.

Effect of a Mediterranean diet intervention on gastrointestinal function in Parkinson's disease (the MEDI-PD study): study protocol for a randomised controlled trial.

INTRODUCTION: Constipation is a common and sometimes debilitating non-motor symptom of Parkinson's disease (PD) that can result in intestinal inflammation and microbial dysbiosis. The Mediterranean diet, rich in fermentable fibres and anti-inflammatory phenolic compounds, is associated with reduced risk of developing PD and slower progression of parkinsonism. The Mediterranean diet is often recommended for people with PD; however, no studies to date examine this diet as a therapeutic intervention to modulate gastrointestinal (GI) dysfunction. METHODS AND ANALYSIS: This is a randomised, controlled, parallel study. During a 2-week run-in, participants with PD and constipation symptoms (n=52) will undergo baseline nutritional and neurological assessments and provide a stool sample. Participants will be stratified by sex and Hoehn and Yahr stage and randomised to follow standard of care for constipation (control) or standard of care plus a Mediterranean diet (intervention) for 8 weeks. A study dietitian will provide dietary instruction and weekly follow-up via telephone to both groups to support adherence and monitor adverse events. Questionnaires will assess dietary intake and GI function including stool frequency, form, symptoms and laxative usage. Measurements completed at baseline will be repeated at 4 and 8 weeks of the intervention. The primary outcome is to evaluate the difference between mean change (final-baseline) in Gastrointestinal Symptom Rating Scale (GSRS) constipation syndrome scores for the control versus intervention groups. Secondary outcomes will assess stool frequency and form, weekly GSRS syndrome scores, digestive quality of life, laxative usage, faecal microbial communities and inflammatory markers, anxiety, depression, quality life, body weight and composition, dietary fibre intake and Mediterranean diet adherence. ETHICS AND DISSEMINATION: The study has received University of Florida Institutional Review Board-01 approval (IRB202001333). Findings will be disseminated via conference presentations, lectures and peer-reviewed publications. TRIAL REGISTRATION NUMBER: NCT04683900.

Mediterranean Diet Adherence in People With Parkinson's Disease Reduces Constipation Symptoms and Changes Fecal Microbiota After a 5-Week Single-Arm Pilot Study.

Introduction: Non-motor symptoms of Parkinson's disease (PD) such as gastrointestinal (GI) dysfunction are common, yet little is known about how modifying dietary intake impacts PD symptoms. The aim of this study in individuals with PD was to determine whether a Mediterranean diet intervention is feasible and affects GI function, intestinal permeability and fecal microbial communities. Methods: A single-arm, 5-week Mediterranean diet intervention study was conducted in eight people with PD. Daily and weekly questionnaires were administered to determine changes in GI symptoms. Urine and stool samples were collected at baseline and after 5 weeks to assess intestinal permeability and fecal microbial communities. Additionally, live-in partners of the participants with PD were matched as controls (n = 8) for baseline urine and stool samples. Results: Participants with PD increased intake of Mediterranean diet based on adherence scores from baseline to week 5 (4.4 ± 0.6 vs. 11.9 ± 0.7; P < 0.01 with >10 representing good adherence), which was linked with weight loss (77.4 kg vs. 74.9 kg, P = 0.01). Constipation syndrome scores decreased after 5 weeks (2.3 ± 0.5 vs. 1.5 ± 0.3; P = 0.04). Bilophila, was higher at baseline in PD (0.6 ± 0.1% vs. 0.2 ± 0.1% P = 0.02) and slightly decreased after the diet intervention (0.5 ± 0.1%; P = 0.01). Interestingly, the proportion of Roseburia was significantly lower in PD compared to controls (0.6 ± 0.2% vs. 1.6 ± 0.3%; P = 0.02) and increased at week 5 (0.9 ± 0.2%; P < 0.01). No differences were observed for markers of intestinal permeability between the control and PD groups or post-intervention. Conclusions: Short-term Mediterranean diet adherence is feasible in participants with PD; correlated with weight loss, improved constipation, and modified gut microbiota. Clinical Trial Registration: ClinicalTrials.gov, identifier: NCT03851861.

Probiotics (Lactobacillus gasseri KS-13, Bifidobacterium bifidum G9-1, and Bifidobacterium longum MM-2) improve rhinoconjunctivitis-specific quality of life in individuals with seasonal allergies: a double-blind, placebo-controlled, randomized trial.

Background: Rhinoconjunctivitis-specific quality of life is often reduced during seasonal allergies. The Mini Rhinoconjunctivitis Quality of Life Questionnaire (MRQLQ) is a validated tool used to measure quality of life in people experiencing allergies (0 = not troubled to 6 = extremely troubled). Probiotics may improve quality of life during allergy season by increasing the percentage of regulatory T cells (Tregs) and inducing tolerance.Objective: The objective of this study was to determine whether consuming Lactobacillus gasseri KS-13, Bifidobacterium bifidum G9-1, and B. longum MM-2 compared with placebo would result in beneficial effects on MRQLQ scores throughout allergy season in individuals who typically experience seasonal allergies. Secondary outcomes included changes in immune markers as part of a potential mechanism for changes in MRQLQ scores.Design: In this double-blind, placebo-controlled, parallel, randomized clinical trial, 173 participants (mean ± SEM: age 27 ± 1 y) who self-identified as having seasonal allergies received either a probiotic (2 capsules/d, 1.5 billion colony-forming units/capsule) or placebo during spring allergy season for 8 wk. MRQLQ scores were collected weekly throughout the study. Fasting blood samples were taken from a subgroup (placebo, n = 37; probiotic, n = 35) at baseline and week 6 (predicted peak of pollen) to determine serum immunoglobulin (Ig) E concentrations and Treg percentages.Results: The probiotic group reported an improvement in the MRQLQ global score from baseline to pollen peak (-0.68 ± 0.13) when compared with the placebo group (-0.19 ± 0.14; P = 0.0092). Both serum total IgE and the percentage of Tregs increased from baseline to week 6, but changes were not different between groups.Conclusions: This combination probiotic improved rhinoconjunctivitis-specific quality of life during allergy season for healthy individuals with self-reported seasonal allergies; however, the associated mechanism is still unclear. This trial was registered at clinicaltrials.gov as NCT02349711.

Health Benefits of Fiber Fermentation.

Although fiber is well recognized for its effect on laxation, increasing evidence supports the role of fiber in the prevention and treatment of chronic disease. The aim of this review is to provide an overview of the health benefits of fiber and its fermentation, and describe how the products of fermentation may influence disease risk and treatment. Higher fiber intakes are associated with decreased risk of cardiovascular disease, type 2 diabetes, and some forms of cancer. Fiber may also have a role in lowering blood pressure and in preventing obesity by limiting weight gain. Fiber is effective in managing blood glucose in type 2 diabetes, useful for weight loss, and may provide therapeutic adjunctive roles in kidney and liver disease. In addition, higher fiber diets are not contraindicated in inflammatory bowel disease or irritable bowel syndrome and may provide some benefit. Common to the associations with disease reduction is fermentation of fiber and its potential to modulate microbiota and its activities and inflammation, specifically the production of anti-inflammatory short chain fatty acids, primarily from saccharolytic fermentation, versus the deleterious products of proteolytic activity. Because fiber intake is inversely associated with all-cause mortality, mechanisms by which fiber may reduce chronic disease risk and provide therapeutic benefit to those with chronic disease need further elucidation and large, randomized controlled trials are needed to confirm causality.Teaching Points• Strong evidence supports the association between higher fiber diets and reduced risk of cardiovascular disease, type 2 diabetes, and some forms of cancer.• Higher fiber intakes are associated with lower body weight and body mass index, and some types of fiber may facilitate weight loss.• Fiber is recommended as an adjunctive medical nutritional therapy for type 2 diabetes, chronic kidney disease, and certain liver diseases.• Fermentation and the resulting shifts in microbiota composition and its activity may be a common means by which fiber impacts disease risk and management.