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A Randomised Controlled Trial Investigating the Impact of Plant Foods on Gastrointestinal and Cardiometabolic Health
Led by King's College London · Updated on 2026-05-14
248
Participants Needed
1
Research Sites
4 weeks
Total Duration
On this page
Sponsors
K
King's College London
Lead Sponsor
B
Biotechnology and Biological Sciences Research Council
Collaborating Sponsor
AI-Summary
What this Trial Is About
Researchers are investigating how plant-based diets affect the gut microbiome diversity and cardiometabolic health in healthy adults aged 30 to 70 years. The study aims to determine the impact of different plant foods on the alpha-diversity of gut bacteria and overall metabolic health. This randomized controlled trial compares two diets containing plant foods to evaluate their effects on gastrointestinal and cardiometabolic markers. Participants will follow one of two provided plant-based diets for four weeks, consuming study meals, snacks, and drinks six days per week. They will self-select foods on one day each week following guidance. The study includes two active comparator diet groups, both emphasizing plant foods but differing in composition. Throughout the trial, participants will attend three visits to provide blood, urine, and stool samples. Researchers will assess body composition, blood pressure, and artery ultrasound measurements. Participants will also complete questionnaires about diet, mental health, physical activity, quality of life, and diet adherence. The main outcome measured is the gut microbiota alpha-diversity at week 4, with various other biological and health markers assessed at baseline and week 4. The total study duration includes the four-week diet intervention and multiple assessments.
CONDITIONS
Brief Title
Effects of Plant Foods on Gastrointestinal and Cardiometabolic Health
Who Can Participate
Eligibility Criteria
You may qualify if you...
- Adults aged 30-70 years
- Ability to give informed consent in English
- Consume equal or less than the average UK plant food intake
- Consume less than 30 g/day of fiber
- BMI between 18.50 and 29.99 kg/m2
- Willing to follow the diet intervention and complete study procedures
- Access to appropriate kitchen equipment and storage for study foods
- Willing to stop prebiotics and probiotics 4 weeks prior and during the study
- Willing to consume animal products daily
- Stable medication use if on hormone replacement therapy for at least 3 months
You will not qualify if you...
- History of diabetes, major psychiatric conditions, eating disorder, alcohol abuse, or recent cancer treatment
- Severe chronic diseases such as neurological, endocrine, renal, cardiac, or pulmonary conditions
- Severe digestive conditions including oesophagitis, gastritis, diverticulitis, Coeliac disease, Crohn's disease, or Ulcerative colitis
- Gut resection surgery (except appendicectomy or cholecystectomy)
- Bleeding disorders, anaphylaxis, or other major conditions affecting study outcomes
- Current diagnosis of IBS as per Rome IV criteria
- Recent use of prebiotics, probiotics, antibiotics, or medications affecting blood pressure, appetite, or metabolism
- Use of dietary supplements other than vitamin D or calcium in the 4 weeks before enrollment
- Allergy or intolerance to study foods
- Unwillingness or inability to consume study foods or comply with protocol
- Pregnancy or lactation
- Unwillingness to consume non-halal or non-kosher products
- Estimated energy needs below 1,500 kcal/day or above 3,000 kcal/day
- Unexplained or unintentional weight loss in past 6 months
AI-Screening
AI-Powered Screening
Complete this quick 3-step screening to check your eligibility
Your Study Journey
Duration - 2 to 4 weeks
Participants are screened for eligibility to participate in the trial.
1 visit (in-person)
Duration - 4 weeks
Participants follow a diet containing plant foods with study meals, snacks, and drinks provided 6 days a week for four weeks. They self-select foods on one day each week.
Weekly visits for up to 4 weeks
Trial Site Locations
Total: 1 location
1
King's College London
London, United Kingdom, SE1 9NH
Actively Recruiting
How is the study designed?
Study Type
INTERVENTIONAL
Masking
TRIPLE
Allocation
RANDOMIZED
Model
PARALLEL
Primary Purpose
PREVENTION
Number of Arms
2
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