Effects of plant foods on gut health and heart health in healthy adults

Is this trial a fit for you?

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

This randomized controlled trial compares two plant-rich diets to see how each affects gut microbiota diversity and cardiometabolic markers in healthy adults. Participants will replace all meals and snacks with study-provided foods for four weeks (six days per week) and attend three visits for blood, urine, stool samples, body composition, an arm artery ultrasound, blood pressure, and questionnaires. The study uses a controlled feeding approach to isolate the effects of diet composition on gut and metabolic outcomes. Outcomes include alpha-diversity of the gut microbiota and various gastrointestinal and cardiometabolic measures. The trial is led by King’s College London with collaboration from partner institutions.

Why it matters

Who can join: the full rules

Inclusion Criteria:

* Adults aged 30-70 years of age
* Capacity to give informed consent in English
* Consume equal or less than the average UK plant food intake (number and quantity)
* Consume less than 30 g/d of fibre
* BMI 18.50-29.99 kg/m2
* Willing to complete the trial by adhering to the diet intervention, complete questionnaires, provide stool, urine and blood samples, record weight and other anthropometric values and record food intake throughout the study
* Willing and able to adhere to the protocol for the diet intervention for the whole duration of the trial (e.g., appropriate space in freezer to store meals, access to oven/microwave, no planned travelling)
* Willing to discontinue use of prebiotics and probiotics 4 weeks prior and during the intervention period
* Willing to consume animal products daily
* Medication use is stable in women receiving hormone replacement therapy (stable use for the past 3 months)

Exclusion Criteria:

* Medical history of any of the following: diabetes, major active or historic psychiatric conditions (e.g., schizophrenia), current eating disorder, alcohol abuse, active treatment for cancer in the last year, severe neurological, endocrine, renal, cardiac or pulmonary disease (or any other chronic medical condition), severe oesophagitis, gastritis or duodenitis, active diverticulitis or intestinal/colonic strictures, Coeliac disease, Crohn's disease or Ulcerative colitis, stem cell or organ transplant, gut resection surgery (excluding appendicectomy and cholecystectomy), bleeding disorder, anaphylaxis or any other major or chronic condition known to impact study outcome measures.
* A current diagnosis of IBS, as defined by the Rome IV criteria.
* Taking medications known to affect outcomes of interest, including:
* Prebiotics and probiotics 4 weeks prior to enrolment.
* Antibiotics within 4 weeks of enrolment.
* Medications known to affect blood pressure, appetite, gut motility, glucose control, or lipid levels within 4 weeks of enrolment.
* Taking any dietary supplements, apart from vitamin D or calcium supplements, 4 weeks prior to enrolment.
* Allergy or intolerance to any study food ingredients.
* Unable/dislike/unwilling to consume study foods or adhere to study protocol (e.g., not willing to drink a maximum 9 units of alcohol a week or consume animal products).
* Currently reported pregnant or lactating.
* Unwilling or unable to consume non-halal or non-kosher products.
* Estimated energy requirements of \<1,500 kcal/day or \>3,000 kcal/day.
* Unexplained or unintentional weight loss in the past six months.

Where it's running

• King's College London
  London, United Kingdom Recruiting

Similar studies

Other studies for the same condition or treatment. Recruiting studies are listed first.

• Yi Jin Jing effects on muscles and bones in healthy adults

  A simple test will see whether Yi Jin Jing exercise affects muscle and bone health in healthy adults aged 18–90.

  Recruiting Beijing Hospital of Traditional Chinese Medicine · Beijing · NCT07753291

• Immun4Cure Cohort of Autoimmune Diseases

  A long-term, 500-person database and biobank is being built to study autoimmune diseases like RA, SLE, and scleroderma, plus healthy adults, using deep profiling and regular follow-ups over five years.

  Recruiting University Hospital, Montpellier · Montpellier · NCT07515638

• How flour milling methods affect blood sugar and gut feelings after eating bread

  In healthy adults who eat bread regularly, this study tests whether bread made from stone-milled flour leads to a smaller rise in blood sugar and fewer gut symptoms than bread made from roller-milled flour.

  Recruiting University of Bergen · Bergen, Vestland · NCT07858110

• Family Good Health Traditions for Life program

  This program will try a community-tailored, family-based version of the Diabetes Prevention Program to help Black parents with prediabetes and their children lower weight and reduce diabetes risk.

  Recruiting Morehouse School of Medicine · Albany, Georgia · NCT07441655

• Intermittent cottonseed oil intake to improve cholesterol and metabolic risk

  This trial will test whether taking cottonseed oil three times a week at two different doses can improve fasting and after-meal blood lipids and other risk markers in adults with high cholesterol or who are overweight.

  Recruiting University of Georgia · Athens, Georgia · NCT07246408

• Daily postbiotic gummy plus nutrition advice for adults with overweight or obesity

  This project will test whether taking a daily postbiotic gummy together with nutritional advice helps adults with overweight or obesity improve body composition, glucose metabolism, and gut microbiota.

  Recruiting Clinica Universidad de Navarra, Universidad de Navarra · Pamplona, Navarre · NCT07165431

How to take part

1. Review the eligibility criteria above with your treating physician.
2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.