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Not yet recruitingNCT07659028BIOTRANSFORMUpdated Jun 22, 2026

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

An interventional study of supplementation, food in Prediabetes, Obesity & Overweight and Inflamation, sponsored by National and Kapodistrian University of Athens. Not yet recruiting at 1 site in Greece. Open to participants aged 30 Years to 50 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-06-22.

Sponsored by National and Kapodistrian University of Athens · Not applicable, Interventional, and Prevention

Phase
Not applicable
Study type
Interventional
Enrollment
60
Allocation
Randomized
Ages
30 Years to 50 Years
Sex
All
01

Study summary

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.

02

Conditions studied

  • Prediabetes
  • Obesity & Overweight
  • Inflamation
  • Oxidative Stress

Keywords

  • FOOD BIOACTIVES
  • FOOD BIOACTIVE COMPOUNDS
  • OLIVE PRODUCTS
  • BILBERRY PRODUCTS
  • OLEA EUROPEA L.
  • BILBERRY
  • VACCINUM MYRTILLOUS L.
  • GUT MICROBIOME
  • MICROBIOME MAPPING
  • IN VITRO
  • IN SILICO
  • BIOACTIVE COMPOUNDS
  • METABOLISM
03

Who can participate

Ages eligible
30 Years to 50 Years
Sexes eligible
All
Accepts healthy volunteers
Yes

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

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
04

Study design

Phase
Not applicable
Primary purpose
Prevention
Allocation
Randomized
Intervention model
Crossover assignment
Masking
Single (Participant)
Enrollment
60 participants (estimated)

Study arms

  • 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

  • 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

Interventions

  • Dietary supplementsupplementation, 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.

    Also known as: Body weight and composition changes, oxidative stress and inflammatory biomarkers, blood samples, urine samples, stool samples

05

What researchers measure

Primary outcomes

  1. Changes in inflammatory and oxidative stress markers

    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

    Time frame: 14 weeks

Secondary outcomes

  1. Lipid profile

    Blood samples: TCHOL, HDL, LDL, TG

    Time frame: 14 weeks

  2. Inflammatory profile

    Blood samples: ICAM-1, VCAM-1, CRP-C

    Time frame: 14 weeks

  3. Anthropometric profile

    Body measurements: BMI and body weight changes

    Time frame: 14 weeks

  4. Metabolic profile

    Urine and plasma samples: metabolite profile in urine and plasma

    Time frame: 14 weeks

  5. Microbiome profile

    Stool samples: microbiome diversity, microbiome composition changes, and microbiome functionality

    Time frame: 14 weeks

06

Study locations

1 site
  • Laiko Hospital
    Athens, 11527, Greece
    • NIKOLAOS TENTOLOURIS, PROFESSOR MD, PHD · Contact · ntentol@meduoa.gr · +30 2132061061
07

Registry details

Key details

Study ID
NCT07659028
Lead sponsor
National and Kapodistrian University of Athens
Responsible party
Nikolaos Tentolouris (Professor of Medicine, National and Kapodistrian University of Athens) — Principal investigator
First posted
Jun 22, 2026
Start date
Jul 1, 2026 (estimated)
Primary completion
Jul 1, 2029 (estimated)
Completion
Oct 31, 2029 (estimated)
Last update
Jun 22, 2026

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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This study is not yet recruiting, as verified in Mar 2026. You cannot join it, but the record below documents what was studied.

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