Healthy Adult VolunteersPLANTIFULNCT07586111
Effects of Plant Foods on Gastrointestinal and Cardiometabolic Health
A study testing A diet containing plant foods and A diet containing different plant foods in people with Healthy Adult Volunteers and Nutrition, run by King's College London at 1 site in United Kingdom.
Trial summary
The aim of this randomised controlled trial is to investigate the effects of plant foods on gastrointestinal and cardiometabolic health in healthy adults aged 30-70 years old. The main question it will answer is "what is the effect of plant foods on alpha-diversity of the gut microbiota?". Read more about this study
- Who is it for?
- Ages 30 to 70 yearsHealthy volunteers can take part
- Conditions the study is for
- Healthy Adult Volunteers, Nutrition
- What is being tested?
- A diet containing plant foods and A diet containing different plant foods
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 248 participants
- Where
- 1 siteUnited Kingdom
- Study dates
- Apr 2026to Nov 2028
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 30 to 70 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- 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
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- 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)
Who cannot join
- 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.
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- 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.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United Kingdom1 site, 1 recruiting
- Recruiting
King's College London
London, SE1 9NH
Clinical Trial Manager, +442078484552, plantiful@kcl.ac.uk
About this study
Official title: A Randomised Controlled Trial Investigating the Impact of Plant Foods on Gastrointestinal and Cardiometabolic Health
The aim of this randomised controlled trial is to investigate the effects of plant foods on gastrointestinal and cardiometabolic health in healthy adults aged 30-70 years old. The main question it will answer is "what is the effect of plant foods on alpha-diversity of the gut microbiota?".
Researchers will compare two diets containing plant foods to see if they have different effects on gastrointestinal and cardiometabolic health.
Read more
Participants will be asked to replace all their meals, snacks and drinks with those provided by the study team for four weeks (6 days/week). Participants will also be asked to attend the research facility on three occasions to:
- Provide a blood sample
- Provide a urine sample
- Provide a stool sample
- Have their body composition assessed
- Have an ultrasound of their artery (arm)
- Have their blood pressure measured
- Answer questionnaires related to dietary intake, mental health, physical activity, quality of life, diet acceptability and adherence
- Conditions
- Healthy Adult Volunteers, Nutrition
- Being tested
- A diet containing plant foods, A diet containing different plant foods
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
A diet containing plant foodsOther
Also called Study Diet A
Study meals, snacks and drinks will be provided that contain plant foods for four weeks (6 days a week). Participants will follow guidance in self-selecting foods on one day per week.
A diet containing different plant foodsOther
Also called Study Diet B
Study meals, snacks and drinks will be provided that contain plant foods for four weeks (6 days a week). Participants will follow guidance in self-selecting foods on one day per week.
| Study group | Role | What they receive |
|---|---|---|
| Study Diet A | Active comparator | Meals, snacks and drinks that contain plant foods provided by the research team for four weeks (6 days a week). Receives: Other: A diet containing plant foods |
| Study Diet B | Active comparator | Meals, snacks and drinks that contain plant foods provided by the research team for four weeks (6 days a week). Receives: Other: A diet containing different plant foods |
What is being measured
The primary outcome is the main question the study is designed to answer.
Alpha-diversity of the gut microbiota
The diversity of microbial taxa in faecal samples at 4 weeks assessed by calculating alpha-diversity score from 16S ribosomal RNA sequencing.
Measured: Week 4
Secondary outcomes (18)
Absolute and change in alpha-diversity of the gut microbiota
Absolute and change in alpha-diversity as measured by the diversity of micriobial taxa in faecal samples via 16S RNA sequencing.
Measured: Baseline, Week 4
Beta-diversity of the gut microbiota
The diversity of microbial taxa in faecal samples by calculating beta-diversity via 16S ribosomal RNA sequencing.
Measured: Baseline, Week 4
Microbiota composition
Absolute and change in microbiota composition of faecal samples between baseline and Week 4 as assessed by 16S ribosomal RNA sequencing.
Measured: Baseline, Week 4
Targeted faecal and plasma metabolomics
Absolute and change in short-chain fatty acids through Liquid Chromatography - Mass Spectrometry using validated assays.
Measured: Baseline, Week 4
Targeted faecal and plasma metabolomics
Absolute and change in bile acids through Liquid Chromatography - Mass Spectrometry using validated assays.
Measured: Baseline, Week 4
Untargeted faecal metabolomics
Metabolomics analysis via 1H NMR spectroscopy.
Measured: Baseline, Week 4
Faecal water content via oven drying
Absolute and change in water content of faecal samples assessed via oven drying.
Measured: Baseline, Week 4
Stool frequency
Absolute and change in stool frequency measured via prospective 7-day stool diary
Measured: Baseline, Week 4
Stool consistency
Absolute and change in stool consistency measured by Bristol stool form scale. Scale from 1 to 7.
Measured: Baseline, Week 4
Gastrointestinal symptoms
Absolute and change in gastrointestincal symptons measured by Gastrointestinal symptoms rating scale score. Scored from 15 to 105 with lower scores indicating less severe symptoms.
Measured: Baseline, Week 4
Endothelial function
Flow mediated dilation measured via ultrasound of arm.
Measured: Baseline, Week 4
Untargeted urine and plasma metabolomics
Metabolomics measured via 1H NMR spectroscopy.
Measured: Baseline, Week 4
Targeted plasma and urine metabolomics
Metabolomics via Liquid Chromatography-Mass Spectroscopy using validated assays.
Measured: Baseline, Week 4
Blood pressure
Absolute and change in diastolic and systolic blood pressure.
Measured: Baseline, Week 4
Body composition
Absolute and change in body composition measured via biolelectrical impedance analysis (BIA).
Measured: Baseline, Week 4
Waist circumference
Absolute and change in waist circumference assessed by tape measure.
Measured: Baseline, Week 4
Dietary intake
Dietary intake measured by aggregating EPIC Norfolk food frequency questionnaire, daily food and drink diaries and food checklists.
Measured: Baseline, Week 4
Biological markers of dietary intake
Absolute and change in biomarkers of dietary intake as measured via validated assays.
Measured: Baseline, Week 4
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted14 May 2026
- Study startApr 2026 (estimated)
- Primary completionOct 2028 (estimated)
- Study completionNov 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Healthy Adult VolunteersStudies of the same condition, open and under way.
- More trials run by King's College LondonThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind
- Who is masked
- Participant, Investigator, Outcomes assessor
- Enrolment
- 248 participants (estimated)
Sponsor and investigators
- Lead sponsor
- King's College London
- Sponsor type
- University, hospital or other
- Collaborators
- Biotechnology and Biological Sciences Research Council, University of Southampton, University of Leeds
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07586111
- Sponsor's protocol ID
- HR-25/26-49752
- Acronym
- PLANTIFUL
- Status last verified
- Oct 2025
- First submitted
- 17 Apr 2026
- Last updated
- 14 May 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 14 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Randomised Controlled Trial Investigating the Impact of Plant Foods on Gastrointestinal and Cardiometabolic Health
- ClinicalTrials.gov ID
- NCT07586111
- Acronym / sponsor ID
- PLANTIFUL / HR-25/26-49752
- Conditions
- Healthy Adult Volunteers, Nutrition
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 248 participants (estimated)
- Lead sponsor
- King's College LondonUniversity, hospital or other
- Collaborators
- Biotechnology and Biological Sciences Research Council, University of Southampton, University of Leeds
- Study start
- Apr 2026 (estimated)
- Primary completion
- Oct 2028 (estimated)
- Study completion
- Nov 2028 (estimated)
- First posted
- 14 May 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The aim of this randomised controlled trial is to investigate the effects of plant foods on gastrointestinal and cardiometabolic health in healthy adults aged 30-70 years old. The main question it will answer is "what is the effect of plant foods on alpha-diversity of the gut microbiota?".
Researchers will compare two diets containing plant foods to see if they have different effects on gastrointestinal and cardiometabolic health.
Participants will be asked to replace all their meals, snacks and drinks with those provided by the study team for four weeks (6 days/week). Participants will also be asked to attend the research facility on three occasions to:
- Provide a blood sample
- Provide a urine sample
- Provide a stool sample
- Have their body composition assessed
- Have an ultrasound of their artery (arm)
- Have their blood pressure measured
- Answer questionnaires related to dietary intake, mental health, physical activity, quality of life, diet acceptability and adherence
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind (participant, investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Study Diet A | Active comparator | Other: A diet containing plant foodsMeals, snacks and drinks that contain plant foods provided by the research team for four weeks (6 days a week). |
| Study Diet B | Active comparator | Other: A diet containing different plant foodsMeals, snacks and drinks that contain plant foods provided by the research team for four weeks (6 days a week). |
Who may qualify
- Ages
- 30 to 70 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (10 listed)
- 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
Key exclusion criteria (13 listed)
- 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.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| A diet containing plant foodsAlso: Study Diet AStudy meals, snacks and drinks will be provided that contain plant foods for four weeks (6 days a week). Participants will follow guidance in self-selecting foods on one day per week. | Other | Study Diet A |
| A diet containing different plant foodsAlso: Study Diet BStudy meals, snacks and drinks will be provided that contain plant foods for four weeks (6 days a week). Participants will follow guidance in self-selecting foods on one day per week. | Other | Study Diet B |
Primary outcome
Alpha-diversity of the gut microbiota
Time frame: Week 4
The diversity of microbial taxa in faecal samples at 4 weeks assessed by calculating alpha-diversity score from 16S ribosomal RNA sequencing.
18 secondary outcomes
Absolute and change in alpha-diversity of the gut microbiota
Time frame: Baseline, Week 4
Beta-diversity of the gut microbiota
Time frame: Baseline, Week 4
Microbiota composition
Time frame: Baseline, Week 4
Targeted faecal and plasma metabolomics
Time frame: Baseline, Week 4
Targeted faecal and plasma metabolomics
Time frame: Baseline, Week 4
Untargeted faecal metabolomics
Time frame: Baseline, Week 4
Faecal water content via oven drying
Time frame: Baseline, Week 4
Stool frequency
Time frame: Baseline, Week 4
Stool consistency
Time frame: Baseline, Week 4
Gastrointestinal symptoms
Time frame: Baseline, Week 4
Endothelial function
Time frame: Baseline, Week 4
Untargeted urine and plasma metabolomics
Time frame: Baseline, Week 4
Targeted plasma and urine metabolomics
Time frame: Baseline, Week 4
Blood pressure
Time frame: Baseline, Week 4
Body composition
Time frame: Baseline, Week 4
Waist circumference
Time frame: Baseline, Week 4
Dietary intake
Time frame: Baseline, Week 4
Biological markers of dietary intake
Time frame: Baseline, Week 4
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 14 May 2026.
- Related InfoLink provided by the sponsor.
- Individual participant dataSharing planned: Undecided
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing A diet containing plant foods and A diet containing different plant foods in people with Healthy Adult Volunteers and Nutrition, run by King's College London at 1 site in United Kingdom.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 10 inclusion and 13 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 14 May 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United Kingdom. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Each site lists its own contact: choose the nearest one under Trial locations. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Alpha-diversity of the gut microbiota (time frame: Week 4). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 14 May 2026.