Gut MicrobiotaNCT03266055
Effects of Blueberry on Gut Microbiota and Metabolic Syndrome
A study testing 50 g of blueberry powder, taken daily for 8 weeks in people with Gut Microbiota and Metabolic Syndrome, run by Laval University at 1 site in Canada.
Trial summary
There is growing evidence that nutritional intervention with dietary polyphenols can positively modulate the gut microbiota to improve cardiometabolic health. Whether the beneficial effects of blueberries on obesity and the metabolic syndrome can be linked to their potential impact on the gut microbiota and intestinal… Read more about this study
- Who is it for?
- Ages 18 to 55 yearsHealthy volunteers can take part
- Conditions the study is for
- Gut Microbiota, Metabolic Syndrome
- What is being tested?
- 50 g of blueberry powder, taken daily for 8 weeks
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 59 participants
- Where
- 1 siteCanada
- Study dates
- 1 Sep 2017to Dec 2028
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 55 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Men and premenopause women in good health
- Caucasians
- At least one of the following : BMI between 25 and 40 kg/m2 or Waist circumference ≥ 80 cm for women and ≥ 94 cm for men
- At least one of the following : TG ≥ 1.35 mmol/L or fasting insulinemia ≥ 42 pmol/L
Who cannot join
- Metabolic disorders (hypertension, diabetes, hypercholesterolemia)
- Regular use of medication affecting study parameters
- Use of natural health product in the last 3 months
- Use of antibiotics in the last 3 months
- Nicotine users
- Allergy or intolerance for blueberries
Show all 11Show fewer
- Blueberry taste aversion
- More than 2 alcohol drinks par day
- Particular dietary habits (vegetarism, gluten-free diet, cetogenic diet...)
- Weight change of more than 5% in the last 3 months
- Surgery in the last 3 months or planed during the study
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Prebiotic Effects of Blueberry in Overweight/Obese Individuals: Potential Role of the Gut Microbiota in Alleviating the Metabolic Syndrome.
There is growing evidence that nutritional intervention with dietary polyphenols can positively modulate the gut microbiota to improve cardiometabolic health. Whether the beneficial effects of blueberries on obesity and the metabolic syndrome can be linked to their potential impact on the gut microbiota and intestinal integrity remains speculative at this time. Moreover, the mechanisms of action underlying health benefits associated to blueberry consumption are still unknown. The investigators are thus proposing to combine the study of metagenomics, transcriptomics and metabolomics to test whether a prebiotic activity of highbush blueberries can play a role in the prevention of obesity-linked metabolic syndrome in a clinical setting.
- Conditions
- Gut Microbiota, Metabolic Syndrome
- Being tested
- 50 g of blueberry powder, taken daily for 8 weeks, 50g of placebo blueberry powder, taken daily for 8 weeks
- Keywords
- Blueberry, Diet
- Medical subject headings
- Metabolic Syndrome
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
50 g of blueberry powder, taken daily for 8 weeksDietary supplement
Subjects will consume blueberry powder during 8 weeks to test the possible effects of blueberries on gut microbiota composition and on metabolic syndrome parameters.
50g of placebo blueberry powder, taken daily for 8 weeksDietary supplement
Subjects will consume blueberry placebo powder to test if there is a significant difference on the impact on gut microbiota composition and metabolic syndrome parameters between this treatment and the active treatment (blueberry powder).
| Study group | Role | What they receive |
|---|---|---|
| Blueberry powder | Experimental | Not described Receives: Dietary Supplement: 50 g of blueberry powder, taken daily for 8 weeks |
| Blueberry placebo powder | Placebo comparator | Not described Receives: Dietary Supplement: 50g of placebo blueberry powder, taken daily for 8 weeks |
What is being measured
The primary outcome is the main question the study is designed to answer.
Changes in plasma insulin/glucose of overweight/obese men and women taking either blueberry powder or placebo blueberry powder
Measured: 12 months
Changes in plasma lipids/lipoproteins of overweight/obese men and women taking either blueberry powder or placebo blueberry powder
Measured: 12 months
Secondary outcomes (6)
Changes in gene expression in overweight/obese men and women taking either blueberry powder or placebo blueberry powder
Measured: 3-6 months
Changes in metabolites concentration in overweight/obese men and women taking either blueberry powder or placebo blueberry powder
Measured: 3-6 months
Changes in the gut microbiota composition in overweight/obese men and women taking either blueberry powder or placebo blueberry powder
Measured: 3-6 months
Changes in blood pressure of overweight/obese men and women taking either blueberry powder or placebo blueberry powder
Measured: 12 months
Changes in intestinal integrity of overweight/obese men and women taking either blueberry powder or placebo blueberry powder
Measured: 12 months
Changes in inflammation biomarkers of overweight/obese men and women taking either blueberry powder or placebo blueberry powder
Measured: 12 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted29 Aug 2017
- Study start1 Sep 2017
- Primary completion14 Jan 2019
- Study completionDec 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Gut MicrobiotaStudies of the same condition, open and under way.
- More trials run by Laval UniversityThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 59 participants (actual)
Sponsor and investigators
- Lead sponsor
- Laval University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Marie-Claude Vohl, Laval University
- Investigators
- Marie-Claude Vohl, Principal investigator, Laval University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03266055
- Sponsor's protocol ID
- BLEUET 2017-135
- Status last verified
- Sep 2026
- First submitted
- 6 Jul 2017
- Last updated
- 8 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Publications
Rousseau M, Horne J, Guenard F, de Toro-Martin J, Garneau V, Guay V, Kearney M, Pilon G, Roy D, Couture P, Couillard C, Marette A, Vohl MC. An 8-week freeze-dried blueberry supplement impacts immune-related pathways: a randomized, double-blind placebo-controlled trial. Genes Nutr. 2021 May 17;16(1):7. doi: 10.1186/s12263-021-00688-2.
PubMed 34000994
Study at a glance
From the registry record, last updated by the sponsor on 8 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Prebiotic Effects of Blueberry in Overweight/Obese Individuals: Potential Role of the Gut Microbiota in Alleviating the Metabolic Syndrome.
- ClinicalTrials.gov ID
- NCT03266055
- Acronym / sponsor ID
- BLEUET 2017-135
- Conditions
- Gut Microbiota, Metabolic Syndrome
- Keywords
- Blueberry, Diet
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 59 participants (actual)
- Lead sponsor
- Laval UniversityUniversity, hospital or other
- Study start
- 1 Sep 2017 (actual)
- Primary completion
- 14 Jan 2019 (actual)
- Study completion
- Dec 2028 (estimated)
- First posted
- 29 Aug 2017 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
There is growing evidence that nutritional intervention with dietary polyphenols can positively modulate the gut microbiota to improve cardiometabolic health. Whether the beneficial effects of blueberries on obesity and the metabolic syndrome can be linked to their potential impact on the gut microbiota and intestinal integrity remains speculative at this time. Moreover, the mechanisms of action underlying health benefits associated to blueberry consumption are still unknown. The investigators are thus proposing to combine the study of metagenomics, transcriptomics and metabolomics to test whether a prebiotic activity of highbush blueberries can play a role in the prevention of obesity-linked metabolic syndrome in a clinical setting.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (participant)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Blueberry powder | Experimental | Dietary Supplement: 50 g of blueberry powder, taken daily for 8 weeks |
| Blueberry placebo powder | Placebo comparator | Dietary Supplement: 50g of placebo blueberry powder, taken daily for 8 weeks |
Who may qualify
- Ages
- 18 to 55 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (4 listed)
- Men and premenopause women in good health
- Caucasians
- At least one of the following : BMI between 25 and 40 kg/m2 or Waist circumference ≥ 80 cm for women and ≥ 94 cm for men
- At least one of the following : TG ≥ 1.35 mmol/L or fasting insulinemia ≥ 42 pmol/L
Key exclusion criteria (11 listed)
- Metabolic disorders (hypertension, diabetes, hypercholesterolemia)
- Regular use of medication affecting study parameters
- Use of natural health product in the last 3 months
- Use of antibiotics in the last 3 months
- Nicotine users
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| 50 g of blueberry powder, taken daily for 8 weeksSubjects will consume blueberry powder during 8 weeks to test the possible effects of blueberries on gut microbiota composition and on metabolic syndrome parameters. | Dietary supplement | Blueberry powder |
| 50g of placebo blueberry powder, taken daily for 8 weeksSubjects will consume blueberry placebo powder to test if there is a significant difference on the impact on gut microbiota composition and metabolic syndrome parameters between this treatment and the active treatment (blueberry powder). | Dietary supplement | Blueberry placebo powder |
Primary outcome
Changes in plasma insulin/glucose of overweight/obese men and women taking either blueberry powder or placebo blueberry powder
Time frame: 12 months
Changes in plasma lipids/lipoproteins of overweight/obese men and women taking either blueberry powder or placebo blueberry powder
Time frame: 12 months
6 secondary outcomes
Changes in gene expression in overweight/obese men and women taking either blueberry powder or placebo blueberry powder
Time frame: 3-6 months
Changes in metabolites concentration in overweight/obese men and women taking either blueberry powder or placebo blueberry powder
Time frame: 3-6 months
Changes in the gut microbiota composition in overweight/obese men and women taking either blueberry powder or placebo blueberry powder
Time frame: 3-6 months
Changes in blood pressure of overweight/obese men and women taking either blueberry powder or placebo blueberry powder
Time frame: 12 months
Changes in intestinal integrity of overweight/obese men and women taking either blueberry powder or placebo blueberry powder
Time frame: 12 months
Changes in inflammation biomarkers of overweight/obese men and women taking either blueberry powder or placebo blueberry powder
Time frame: 12 months
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 8 Sep 2026.
- Derived from this study: PubMed 34000994Rousseau M, Horne J, Guenard F, de Toro-Martin J, Garneau V, Guay V, Kearney M, Pilon G, Roy D, Couture P, Couillard C, Marette A, Vohl MC. An 8-week freeze-dried blueberry supplement impacts immune-related pathways: a randomized, double-blind placebo-controlled trial. Genes Nutr. 2021 May 17;16(1):7. doi: 10.1186/s12263-021-00688-2.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Marie-Claude Vohl principal investigator
Laval University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing 50 g of blueberry powder, taken daily for 8 weeks in people with Gut Microbiota and Metabolic Syndrome, run by Laval University at 1 site in Canada.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 11 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: under way, not looking for participants, as of the sponsor's last update on 8 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Canada. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Changes in plasma insulin/glucose of overweight/obese men and women taking either blueberry powder or placebo blueberry powder (time frame: 12 months). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT03266055, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 8 Sep 2026.