Effects of Plant Foods on Gastrointestinal and Cardiometabolic Health

ConditionsHealthy Adult Volunteers Nutrition

Trial statusRecruiting

Trial phaseNot applicable

Trial typeInterventional

Biological sexAll

Age30-70

SponsorKing's College London

About this trial

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

Eligibility criteria

This trial accepts healthy volunteers

Qualifiers

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

Disqualifiers

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.

Prebiotics and probiotics 4 weeks prior to enrolment.

Antibiotics within 4 weeks of enrolment.

Trial design

Design model

Parallel

Treatments tested in this trial

A diet containing plant foods
Other intervention
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 foods
Other intervention
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.

Treatment groups

248 Participants

are divided into 2 treatment groups

Group A: Study Diet AActive comparator 1 intervention

Group B: Study Diet BActive comparator 1 intervention

Trial outcomes

Primary outcomes

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.

Time frame

Week 4

Secondary outcomes

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.

Time frame

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.

Time frame

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.

Time frame

Baseline, Week 4

Targeted faecal and plasma metabolomics

Absolute and change in short-chain fatty acids through Liquid Chromatography - Mass Spectrometry using validated assays.

Time frame

Baseline, Week 4

Other outcomes

Health-related Quality of Life

Absolute and change in SF-36 questionnaire scores.

Time frame

Baseline, Week 4

Mental Health

Absolute and change in Patient Health Questionnaire-8 and Anxiety and Depression Scale scores.

Time frame

Baseline, Week 4

Diet acceptability

Acceptability of diet measured through a diet acceptability questionnaire containing multiple choice and open-ended questions.

Time frame

Baseline, Week 4

Diet satisfaction

Absolute diet satisfaction measured by Food benefits assessment scale. Scored from 41 to 205 with a lower score indicating a higher diet satisfaction.

Time frame

Week 4