Ellagic Acid, Urolithin and Colonic Microbial Communities Affected by Walnut Consumption

November 24, 2021 updated by: Daniel Rosenberg, UConn Health
Briefly, this is a 28-day dietary intervention study participants will be asked to eat 2 ounces (52 grams) of walnuts every day for 3 weeks, and at the end of the study period they will come in for a colonoscopy. Participants will first start a 1-week run-in period where they will be asked to avoid foods high in ellagic acid. In addition, they will be asked to complete food surveys and two sets of 3-day dietary records, and to provide colon biopsies for this study during their routine colonoscopy, as well as a blood, and two urine and stool samples. Urine samples will be used for analysis of urolithin, ellagic acid metabolites. Stool samples will be used to assess gut microbiota changes after walnut consumption. Dietary records will be used for compliance and Food Frequency Questionnaire will be used to assess dietary habits. Lastly, the biopsy samples will be used for analysis of biomarkers and anti-inflammatory in the colon, as well as adherent microbiome to the colonic tissue. Data will be analyzed based on the urolithin phenotypes.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

The investigators propose to address the influence of ellagic acid obtained from walnuts and its microbial-derived metabolites (urolithin) on the gut microbiome and inflammation-related biomarkers in a human clinical study. Patients will be enrolled and detailed demographic and dietary information, biopsy specimens through colonoscopies, as well as fecal, blood and urine samples will be collected. The wide range of gut urolithin levels provides the rationale for our proposed studies. Will the specific urolithin phenotypes show a disparate range of chemopreventive (anti-inflammatory) response to walnut consumption? The hypothesis is that walnut ingestion in "Phenotype A" participants (producing the highest levels of urolithin) will be associated with a beneficial anti-inflammatory response as tested in colonic mucosa and a higher abundance of bacterial species associated with ellagic acid metabolism. Although 16S ribosomal ribonucleic acid gene (rRNA) sequencing allows inexpensive bacterial identification at the genus/species level, a whole genome sequencing (mWGS) will be employed to achieve finer classification (strain level), and identify other microbes (e.g., viruses, fungi, small eukaryotes). Furthermore, mWGS targets the entire genome of each microbe (not just the 16S rRNA gene), allowing for construction of a microbial gene catalogue, including a metabolic pathway description for each sample. This will characterize the functional potential of the microbial community. Ultimately, the proposed studies will inform the application of prebiotic to enhance the formation of urolithin metabolites from ellagic acid for the prevention of inflammation-associated Colorectal Cancer, a development that would have significant translational implications.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
47

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

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

Study Locations

  • United States
    • Connecticut
      • Farmington, Connecticut, United States, 06030
        • University of Connecticut Health Center

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

46 years to 61 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Men or women between the ages of 50-65 years old who are scheduled to undergo a routine screening colonoscopy
  • English speaking/reading patients willing and able to provide written informed consent for study participation
  • Patients willing to consume walnuts for 3 weeks
  • Willingness to comply with all study requirements

Exclusion Criteria:

  • Current active malignancy, previous history of gastrointestinal malignancy, or altered gastrointestinal anatomy
  • Current evidence or previous history of ulcerative colitis or Crohn's disease
  • HIV infection, chronic viral hepatitis
  • Allergy to walnuts or hypersensitivity to tree nuts
  • Use of antibiotics within the past month
  • Individuals with blood coagulation disorders or on anti-coagulant therapy
  • Treated with steroids, immunosuppressive agents or other anti-inflammatory drugs one week prior to starting intervention
  • Non-English-speaking patients who require an interpreter to give consent
  • Patients residing in the Department of Correction
  • Inability to comply with the protocol requirements
  • Any other condition that, in the opinion of the PI, might interfere with study objectives

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

  • Primary Purpose: Prevention
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Walnut Consumption
After screening, participants will avoid foods high in ellagic acid. These foods include pomegranates, hazelnuts, pistachios, strawberries, raspberries, blackberries, oak-aged wines, spirits, and walnuts (besides the ones given by researchers); a complete list will be provided to the subjects. Participants will then return to research facility and provide urine and stool samples, as well as a set of 3-day dietary records. Then, they will start to consume 2 ounces of walnuts per day for 21 days with their usual diet. At the end, they will collect another urine and stool sample as well as another set of dietary records, and then come in for the scheduled colonoscopy where they will be asked to provide biopsy specimens. That completes the intervention and participation in the study.
Other: Walnuts
Participants will consume 2 ounces of walnuts for 21 days

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Leve of Urolithin of this Population
Time Frame: 28 days post walnuts
Urolithin will be measure in urine using a mass spectrometer to characterize this population into three know urolithin phenotypes, Uro-A, Uro-B and Uro-0, after walnut consumption.
28 days post walnuts
Urolithin Phenotype and Colonic Health
Time Frame: 28 days post walnuts
Assess biomarkers in colonic mucosa from biopsy samples collected at colonoscopy that are associated with the three different urolithin metabotype following walnut consumption. This biomarkers is a total of 287 genes involved in cellular apoptosis and proliferation, inflammation and senescence, including TIMP1 (used for power calculations), cytokine and T cell and B cell signaling genes, as well as markers of lymphocyte subsets and immune checkpoint pathways and targets, providing a wide range of functional annotation groups.
28 days post walnuts

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Identify Changes in Microbiota and Microbes Responsible for Urolithin Formation Followed by Walnuts Consumption using Metagenomics Sequencing
Time Frame: Day 7 to Day 28
Microbiome will be analyzed before and after walnut consumption with the goal to identify microbes responsible for urolithins production. DNA will be extracted from fecal samples and the V1-3 hyper-variable region of bacterial 16S rRNA genes will be sequenced to analyze bacterial community structure. Although 16S rRNA gene sequencing allows inexpensive bacterial identification to the genus/species level, mWGS will be employed in order to achieve finer classification (strain level), and identify other microbes, including viruses, fungi and small eukaryotes.
Day 7 to Day 28

Collaborators and Investigators

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

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
UConn Health

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
California Walnut Commission
American Institute for Cancer Research
The Jackson Laboratory

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Study Chair: JOHN BIRK, MD, UConn Health
  • Principal Investigator: DANIEL W ROSENBERG, PhD, UConn Health

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)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
May 20, 2019

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
April 8, 2021

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
April 8, 2021

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
August 20, 2019

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 22, 2019

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
August 26, 2019

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
November 26, 2021

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
November 24, 2021

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
November 1, 2021

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 19-121JS-1

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

No

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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