Condition category
Nutritional, Metabolic, Endocrine
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status
No longer recruiting
Publication status

Plain English Summary

Background and study aims
Both high levels of blood lipids (cholesterol) and oxidative stress have an impact on the risk of cardiovascular diseases. Previous studies have shown that the antioxidative probiotic L. fermentum ME-3 has a positive effect on blood lipid levels. We are carrying out a study to investigate the effects of kefir (a fermented milk drink) with probiotic L. fermentum ME-3 on healthy volunteers with high levels of blood lipids.

Who can participate?
Persons with elevated blood levels of triglycerides, cholesterol and its fractions.

What does the study involve?
Eligible participants will be randomly allocated to either the probiotic group or the placebo group. The probiotic group will receive the probiotic kefir and the placebo group will receive a dummy probiotic kefir for 8 weeks. Body measurements, clinical data, blood, urine and faecal samples will be collected and analysed. The measurements will be carried out at the start of the study and after 4 weeks and 8 weeks.

What are the possible risks and benefits of participating?
Participants will undergo a range of tests to discover their risk of developing cardiovascular and other chronic diseases. There are no expected risks in participating, except a small risk of bruising from giving the blood sample.

Where is the study run from?
The study is conducted by Bio-Competence Centre of Healthy Dairy Products, Estonia.

When is the study starting and how long is it expected to run for?
The study started in February 2012 and will run until December 2014.

Who is funding the study?
Archimedes Foundation of Ministry of Science and Education, Estonia and University of Tartu, Estonia.

Who is the main contact?
Prof. Marika Mikelsaar:
Prof. Mihkel Zilmer:

Trial website

Contact information



Primary contact

Prof Marika Mikelsaar


Contact details

University of Tartu
Faculty of Medicine
Department Microbiology
Department of Biochemistry
Ravila 19

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title

Effect of kefir containing probiotic L. fermentum ME-3 on blood indices of healthy volunteers in a randomized double-blinded controlled parallel-designed two-armed study


Study hypothesis

The consumption of kefir with probiotic L. fermentum ME-3 helps to improve the indices of serum lipids and oxidative stress markers in pre-selected healthy individuals with borderline values of blood triglycerides, cholesterol and its fractions.

Ethics approval

Human Research Ethics Review Committee, University of Tartu, 19/12/2011, ref.: 210/T-3

Study design

Randomized double-blind controlled parallel-designed two-armed intervention phase II trial

Primary study design


Secondary study design

Randomised controlled trial

Trial setting


Trial type


Patient information sheet

Not available in web format, please use the contact details below to request a patient information sheet


Elevated values of blood triglycerides, blood cholesterol and its fractions


Blocked randomization lists were produced by the statistician and held centrally.

The consumption of a probiotic kefir comprising Lactobacillus fermentum strain ME-3: daily dose of kefir 200 ml, daily dose of probiotic: 8x10^9 colony forming units for 8 weeks vs consumption of control kefir 200 ml. The participants provided blood samples four times: at selection, at the start and after 4 and 8 weeks; stool and urine samples were collected three times: at the start and after 4 and 8 weeks of intervention.

Intervention type



Phase II

Drug names

Primary outcome measure

Cardiovascular health:
1. Significant decrease of LDL-cholesterol
2. Significant decrease of triglycerides

Protection against oxidative damage:
1. Significant decrease of oxidized LDL
2. Significant decrease of urinary isoprostanes

Secondary outcome measures

Cardiovascular health:
In probiotic group maintenance or significant reduction (p<0.05) of:
1. HDL-cholesterol
2. Homocysteine
3. ApoB/apoA1
4. hs-CRP
5. Leptin
6. Adiponectin
7. Blood pressure

Protection against oxidative damage:
In probiotic group maintenance or significant reduction (p<0.05) of:
1. Oxidative stress index (OSI)
2. Glutathione redox status (GSSG/GSH)
3. MPO
4. IL-6
5. TNF-alpha

Temporal colonization of GI tract with L. fermentum ME-3 detected in faecal samples.

Measured at baseline, at the 4th week and the 8th week from the beginning of the trial.

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1. A written informed consent
2. Age between 35 and 65 years
3. No known health problems
4. Elevated levels of blood total cholesterol/cholesterol fractions: >3.4 mmol/l for LDL, >3.0 mmol/l for the LDL/HDL ratio, >5.2 mmol/l for the total cholesterol and >1.7mmol/l for the level of triglycerides
5. No use of any concomitant treatment which could influence the evaluation of the efficacy and the tolerability of the investigational study product, including lipid-lowering drugs (e.g. statins, bile acid sequestrates, cholesterol absorption inhibitors, nicotinic acid), supplementation with e.g. omega-3 fatty acids, calcium, oat fiber, niacin, green tea extract, plant sterols, soy protein, psyllium seed husk or probiotics/prebiotics within the preceding 2 months
6. Willingness to maintain a stable diet and physical activity level
7. Normal or not clinically pronounced safety lab values (clinical chemistry, blood count) except for lipids

Participant type


Age group




Target number of participants


Participant exclusion criteria

1. Pregnancy and breastfeeding
2. A history of gastrointestinal disease, food allergy, diabetes
3. Acute infection within the last 2 weeks prior to enrolment
4. Use of any antimicrobial agents within the preceding 2 months or use of any regular concomitant medication including any non-steroidal anti-inflammatory drugs and antioxidant products 2 weeks
5. Intolerance to the investigational product / its ingredients
6. Any kind of concurrent disease which could influence the evaluation of the efficacy and the tolerability of the investigational study product
7. Any serious organ or systemic diseases
8. High blood pressure (e.g. >140/95 mm Hg)
9. Eating disorder
10. Extensive exercise
11. Genetic hyperlipidemia
12. Drug or alcohol abuse
13. Active weight loss > 5 kg in prior 3 months
14. Participation in other studies within the last 30 days / during the study

Recruitment start date


Recruitment end date



Countries of recruitment


Trial participating centre

University of Tartu

Sponsor information


Tere AS (Estonia)

Sponsor details

Pärnu mnt 139c

Sponsor type




Funder type


Funder name

Archimedes Foundation of Ministry of Science and Education (Estonia)

Alternative name(s)

Funding Body Type

Funding Body Subtype


Funder name

University of Tartu (Estonia) - Faculty of Medicine, Dept. of Microbiology and Dept. of Biochemistry

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date

Participant level data

Not provided at time of registration

Basic results (scientific)

Publication list

2015 results in:

Publication citations

Additional files

Editorial Notes