Research Projects
Healing the gut: A randomized controlled pilot trial on the effects and feasibility of Mediterranean diet (MedDiet) on constipation and gut microbiome in people with Parkinson’s disease

Programme(s) to which this project applies:

☑ MPhil/PhD ☒ MRes[Med] ☒ URIS

Constipation is the most common gastrointestinal symptom of Parkinson’s disease (PD), affecting up to 90% of patients. Constipation is associated with bloating and discomfort, impaired levodopa response, and poor health-related quality of life (HRQOL). Recent research has highlighted the role of gut-brain axis in PD progression. In particular, microbiota dysbiosis is associated with a wide range of gastrointestinal symptoms, including constipation, and may worsen disease prognosis via increased intestinal permeability, intestinal inflammation, and neuroinflammation.

Increasing evidence supports that the Mediterranean diet (MedDiet) is associated with modulated gut microbiome and overall gut health. MedDiet is high in dietary fiber that may exert very desirable therapeutic effects in combatting constipation. Besides, evolving evidence suggests the anti-inflammatory and anti-oxidant roles of MedDiet may be appealing as a disease-modifying strategy toward PD neurodegeneration. However, the effects and acceptability of adopting MedDiet on alleviating constipation and promoting gut microbiome in Chinese PD patients remains unexplored.

The study will be an assessor-blinded two-arm randomized controlled pilot trial with a sequential mixed-methods design to examine the preliminary effects and acceptability of an 8-week MedDiet counselling program compared with habitual diet control. Repeated outcome measures will be assessed at the three time-points: (i) baseline and (ii) 4-week (T1) and (iii) 8-week intervention (T2). Qualitative interviews will be conducted at T2 to explore their overall experience of using MedDiet. The study’s development-evaluation-implementation process will follow the Medical Research Council’s framework for complex interventions36.

Project objectives:
1. To compare the effects of MedDiet versus habitual diet on the number of complete bowel movements, and the secondary outcomes included the number of bowel movements, stool consistency, laxative use, gut microbiome diversity and microbial biomarkers, PD-related motor and non-motor symptoms, and HRQOL among Chinese Parkinson’s disease (PD) patients over the 8-week study period.
2. To explore the experiences of Chinese PD patients using MedDiet as a lifestyle intervention for constipation management, particularly the perceived effects and the conditions that may influence their motivation, acceptability and long-term practice using a qualitative research approach.

Professor YY Kwok, School of Nursing

Professor Jojo Kwok is an Assistant Professor at the School of Nursing, The University of Hong Kong, as well as a registered nurse and certified yoga instructor in Hong Kong. Her research focuses on chronic illness care, gerontology, mental health and behavioral medicine, with a special emphasis on Parkinson’s disease. Her ongoing research projects include the effects and mechanisms of individual mindfulness techniques in people with Parkinson’s disease. Her research findings have been published in leading international journals such as JAMA Neurology, Journal of the American Medical Directors Association and Journal of Neurology, and featured as impactful news in both local and international mass media, including Reuters Health and Radio Television Hong Kong. She has also been invited to present in international conferences such as the International Conference on Frontiers in Yoga Research and its Applications (INCOFYRA) and Symposium on Yoga Research. She has received an Outstanding New Researcher Award, an Early Career Award and a Meritorious Scientific Abstract Award offered by the International Society of Behavioral Medicine (ISBM) in 2021 and 2018, respectively.

In addition to her research achievement, Professor Kwok has received a Pi Iota Chapter Scholarship Award (Nurse Leader) in 2020 from The Sigma Theta Tau International Honor Society of Nursing in recognition of her significant contribution and leadership in community services. She has been appointed as an external reviewer for national competitive research grants such as the Dutch Research Council (NOW) Talent Programme and the Austrian Science Fund. She is dedicated to her profession. She has been appointed as a council member of the Hong Kong Parkinson's Disease Foundation (HKPDF) in 2022, and a committee member of the HKPDF Education and Training Committee since 2016 to contribute to quarterly education materials regarding evidence-based nursing practice for Parkinson’s disease.

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For more information or to express interest for this project, please email the supervisor or the specified contact point in the project description.  Interested candidates are advised to enclose with your email:

  1. your CV,
  2. a brief description of your research interest and experience, and
  3. two reference letters (not required for HKUMed UG students seeking MRes[Med]/URIS projects).

Information on the research programme, funding support and admission documentations could be referenced online at the Research Postgraduate Admissions website. General admission enquiries should be directed to

HKUMed MBBS students interested in the Master of Research in Medicine (MRes[Med]) programme may visit the programme website for more information.  

HKUMed UG students interested in the Undergraduate Research Internship Scheme (URIS) may visit the scheme’s website for more information.