DIetary plAnt Extracts, Colonic MicrObes, and Apoe geNetics Interactions stuDy (DIAMOND)

December 6, 2023 updated by: University of East Anglia
This study will involve donating a salivary sample and a faecal (stool) sample. These will be analysed in the laboratory to determine the forms of the APOE gene you are carrying (your APOE genotype) and the response of the bacteria in your colon to reactive compounds extracted from edible plants (dietary bioactives).

Study Overview

Status

Recruiting

Conditions

Detailed Description

In an ageing population, the incidence of dementia is rapidly increasing and poses a significant financial, societal, and above all, personal burden. Aside from ageing, the type of APOE gene an individual carries (their APOE genotype) is the greatest risk factor for the development of cognitive decline. It has been shown that the APOE genotype of an individual influences the types of bacteria present in the colon. The bacteria which reside in the colon have recently emerged as a significant contributor to nutrition and health and have been suggested to influence brain functioning through complex connections between the gut and the brain.

Nutrition is considered important for brain function throughout life, and findings from recent laboratory and human observational studies have suggested that reactive compounds extracted from edible plants (dietary bioactives) can not only improve brain function, but they can change the function and composition of gut bacteria. Dietary bioactives are a range of natural compounds found in great concentrations within fruits and vegetables which influence the body. An example of a dietary bioactive is a group of compounds known as polyphenols. These polyphenols are described as antioxidants and are found in various foods, including berries, tea, and cocoa.

There have been no previous studies looking at the impact of dietary bioactives on the microbiome of each APOE genotype and the metabolites produced by each of these bacteria. We aim with the current study to identify how dietary bioactives from a range of plant tissue could influence gut bacteria present and the metabolites produced by the bacteria in each APOE group, and the compounds produced by these bacteria.

What will the study involve? Once we have established a potentially suitable participant, they will be sent a salivary sampling kit. Depending on the genotype, age and sex, participants will be requested to donate a stool sample. The stool will be processed in a colon model with cocoa polyphenol added.

The study involves the following stages:

  1. Online screening, consenting, and collection of basic information
  2. Collection of a salivary sample in person at the Clinical Research Facility or home and return to the labs via pre-paid postal mail.
  3. Confirmation of eligibility to donate stool samples.
  4. Collection of stool samples on the same day as sample collection. Returning the sample in person or through the pre-paid postal system.

Study Type

Observational

Enrollment (Estimated)

64

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Sampling Method

Non-Probability Sample

Study Population

Healthy adults who fit the above inclusion and exclusion criteria. Able to donate a stool and salivary sample.

Description

Inclusion Criteria:

  • Aged between 18-35 years old or aged 55+ years old
  • Fluent in written and spoken English and capacity to consent
  • Availability to take part in the study

Exclusion Criteria:

  • Participants will be excluded from donating if they have been diagnosed with any gastrointestinal conditions such as inflammatory bowel disease.
  • They will also be excluded if they have a diagnosis of any form of dementia or severe cognitive impairment.
  • They currently consume a high flavonoid intake defined as >15 portions of flavonoid rich food per day.
  • History or MRI evidence of brain damage, including significant trauma, stroke, learning difficulties or serious neurological disorder, including a loss of consciousness for more than 24 hours.
  • Currently smoking or ceased smoking less than 6 months ago.
  • Chronic fatigue syndrome, liver disease, diabetes mellitus, or gall bladder abnormalities.
  • History of alcohol or drug dependency.
  • Clinically diagnosed psychiatric disorder.
  • Currently a participant or have been a participant in any other study involving an investigational product within the last 4 weeks.
  • Received a COVID-19 diagnosis within the last 30 days

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Prospectively genotyped participants
These participants will be advertised to in the local area. They will be genotyped for their APOE genotype, and then the stool sample will be collected.
Database participants
Participants from the previously genotyped cohort "Early sleep and circadian markers of Alzheimer's disease: the impact of APOE-ε4 on circadian rhythm and sleep-wake homeostasis in humans" (Reference: 2017/18-135) who have consented to be contacted will be contacted to collect a stool sample.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Whether there is a significant difference between the in vitro metabolism of flavan-3-ols using a human colon model
Time Frame: 09/2025
Participants will be genotyped for their APOE genotype. They will then be requested to donate a stool sample. This stool sample will be run through a colon.model inoculated with flavan-3-ols to determine whether there is a significant difference between the genotypes. Flavan-3-ol metabolism will be measured with LCMS
09/2025
Determine whether there are significant differences between the composition of the gut microbiome of each APOE genotype.
Time Frame: 09/2025
Participants will be genotyped for their APOE genotype. Their stool sample will then have its gut microbiome analysed. Metagenomic techniques will be utilised to analyse the microbiome
09/2025

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of East Anglia

Collaborators

Quadram Institute Bioscience

Investigators

  • Principal Investigator: David Vauzour, PhD, University of East Anglia

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

June 19, 2023

Primary Completion (Estimated)

January 1, 2025

Study Completion (Estimated)

September 1, 2025

Study Registration Dates

First Submitted

June 6, 2023

First Submitted That Met QC Criteria

June 6, 2023

First Posted (Actual)

June 15, 2023

Study Record Updates

Last Update Posted (Estimated)

December 7, 2023

Last Update Submitted That Met QC Criteria

December 6, 2023

Last Verified

April 1, 2023

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 319832

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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