Human Pilot Study for the Investigation of the Role of Bilberry and Olive Bioactives on Oxidative Stress Parameters and Inflammatory Markers. (BIOTRANSFORM)

June 15, 2026 updated by: Nikolaos Tentolouris, National and Kapodistrian University of Athens

A Blinded Placebo-controlled Human Pilot Study for the Investigation of the Role of Bilberry and Olive Bioactives on Oxidative Stress Parameters and Inflammatory Markers. Relevance in European Population

Numerous plant-based foods contain bioactive compounds, in particular polyphenols, which have antioxidant, anti-inflammatory, and metabolic regulatory effects. These so-called food bioactives (FB) are converted in the human organism, in particular by the gut microbiota and microsomal (liver/intestinal) metabolism, into numerous metabolites, which often represent the actual biologically active molecules. As part of the European HORIZON-MSCA Doctoral Network "BioTransform," two such food models are being studied as examples: 1. Olive products (Olea europaea L.) - representative of the Mediterranean diet, rich in secoiridoids and phenylethanols (especially hydroxytyrosol and tyrosol). 2.

Bilberry /blueberry (Vaccinium myrtillus L.) - representative of the Central European diet, rich in anthocyanosides. Two parallel human intervention studies will be conducted, one in Graz (WP1, DC5) and one in Athens (WP1, DC3). These pilot studies will generate biological samples (blood, urine, stool) and investigate the extent to which taking these standardized dietary supplements influences glucose metabolism and markers of oxidative stress and low-grade inflammation.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

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.

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 (Estimated)

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.
60

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

  • Greece
      • Athens, Greece, 11527
        • Laiko Hospital
        • Contact:
          • NIKOLAOS TENTOLOURIS, PROFESSOR MD, PHD
          • Phone Number: +30 2132061061
          • Email: ntentol@meduoa.gr

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

  • Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • 30-50 years old,
  • BMI> 25 kg/m2
  • prediabetic stage
  • hsCRP> 2mg/ L
  • HbA1c 5,7-6,4%
  • Impaired fasting glucose (IFG)
  • Caucasian

Exclusion Criteria:

  • No signed informed consent
  • Supplementation or probiotic usage in the past 8 weeks
  • Chronic gastrointestinal, inflammatory or metabolic diseases
  • Alcohol misuse
  • Pregnancy or breastfeeding
  • Acute infection during the past month

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: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: Single

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: INTERVENTION WITH OLIVE OIL EXTRACTS
Group of 20 people will receive olive oil extract supplements and after the washout period will receive placebo.
Dietary supplement: supplementation, food
Through this pilot clinical study, the possible change of inflammatory and oxidative stress biomarkers in prediabetic, overweigh/ obese people will be observed. Blood, urine and stool samples will be collected, while weight mangment will also be controlled.
Other Names:
  • blood samples
  • Body weight and composition changes
  • oxidative stress and inflammatory biomarkers
  • urine samples
  • stool samples
Experimental: INTERVENTION WITH BILBERRY
Group of 20 participants will receive bilberry extract supplements and after the washout period a placebo phase.
Dietary supplement: supplementation, food
Through this pilot clinical study, the possible change of inflammatory and oxidative stress biomarkers in prediabetic, overweigh/ obese people will be observed. Blood, urine and stool samples will be collected, while weight mangment will also be controlled.
Other Names:
  • blood samples
  • Body weight and composition changes
  • oxidative stress and inflammatory biomarkers
  • urine samples
  • stool samples

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
Changes in inflammatory and oxidative stress markers
Time Frame: 14 weeks
The changes in the inflammatory and oxidative stress markers will be assessed through blood samples and the biomarkers: hsCRP, IL-6, TNF-a, total antioxidant capacity, ratio glutathione/ oxidiced glutathion
14 weeks

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
Lipid profile
Time Frame: 14 weeks
Blood samples: TCHOL, HDL, LDL, TG
14 weeks
Inflammatory profile
Time Frame: 14 weeks
Blood samples: ICAM-1, VCAM-1, CRP-C
14 weeks
Anthropometric profile
Time Frame: 14 weeks
Body measurements: BMI and body weight changes
14 weeks
Metabolic profile
Time Frame: 14 weeks
Urine and plasma samples: metabolite profile in urine and plasma
14 weeks
Microbiome profile
Time Frame: 14 weeks
Stool samples: microbiome diversity, microbiome composition changes, and microbiome functionality
14 weeks

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.
National and Kapodistrian University of Athens

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 (Estimated)

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.
July 1, 2026

Primary Completion (Estimated)

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.
July 1, 2029

Study Completion (Estimated)

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.
October 31, 2029

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).
June 9, 2026

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.
June 15, 2026

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.
June 22, 2026

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.
June 22, 2026

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.
June 15, 2026

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.
March 1, 2026

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.
  • 999643007
  • 101225248 (Other Grant/Funding Number: Marie Skłodowska-Curie Actions)

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.

Clinical Trials on Oxidative Stress

Clinical Trials on supplementation, food

Search Similar Trials

Sponsors and Collaborators

Medical Conditions

Drug Interventions

Conditions

Rare Diseases

Drug Interventions

Dietary Supplements

Sponsor/Collaborators

Locations

Cookie Settings

We use cookies to ensure that we give you the best experience on our website. For more details carefully read our Privacy and Cookies Policy. ...>>>You can change your preferences or withdraw your consent at any time by deleting the cookies from your website or computer as described in the policy. Please accept it and choose your preferences by ticking the corresponding boxes in the "Manage Settings" section below. Please carefully read our Terms of Service before you proceed with using any part of this website.
«Manage Settings