Effect of probiotic yoghurt on blood indices and intestinal microflora of healthy volunteers

ISRCTN	ISRCTN68198472
DOI	https://doi.org/10.1186/ISRCTN68198472
Protocol serial number	178/T-13
Sponsor	Bio-Competence Centre of Healthy Dairy Products Ltd. (Estonia)
Funders	EU Structural Funds (Estonia) - http://www.struktuurifondid.ee/, Enterprise Estonia (Estonia) - http://www.eas.ee

Submission date: 25/02/2009
Registration date: 06/03/2009
Last edited: 06/03/2009

Recruitment status: No longer recruiting
Overall study status: Completed
Condition category: Other

Prospectively registered

Protocol

Statistical analysis plan

Results

Individual participant data

Record updated in last year

Plain English summary of protocol

Not provided at time of registration

Contact information

Prof Marika Mikelsaar
Scientific

Tartu Ulikool
Ravila 19
Tartu
50411
Estonia

Phone	+372 (0)7 374 179
Email	marika.mikelsaar@ut.ee

Study information

Primary study design	Interventional
Study design	Randomised double-blind cross-over trial
Secondary study design	Randomised controlled trial
Study type	Participant information sheet
Scientific title	Effect of probiotic yoghurt on blood indices and intestinal microflora of healthy volunteers: a randomised double-blind cross-over trial
Study acronym	YOG
Study objectives	The consumption of probiotic Lactobacillus plantarum containing yoghurt impacts positively on intestinal microflora, blood pressure and immunological parameters of healthy volunteers.
Ethics approval(s)	Ethics Review Committee on Human Research of the University of Tartu, approved on 19/01/2009 (ref: 178/T-13)
Health condition(s) or problem(s) studied	Intestinal microflora, blood pressure and immunological parameters of healthy adults
Intervention	Probiotic yoghurt consumption versus regular yoghurt consumption. Volunteers are randomly allocated to receive either: 1. 150 g probiotic yoghurt (group 1) or control yoghurt (group 2) once a day for 3 weeks. Probiotic yoghurt containing Lactobacillus plantarum strain 3 x 10^9 colony forming units [CFU] per g of yoghurt. 2. After a two-week washout period, volunteers will be crossed over to another three weeks.
Intervention type	Drug
Phase	Not Applicable
Drug / device / biological / vaccine name(s)	Lactobacillus plantarum
Primary outcome measure(s)	The following will be measured at recruitment, after 3-week intervention, after 2-week washout and at the end of another 3-week intervention: 1. Clinical blood indices 2. Intestinal microflora
Key secondary outcome measure(s)	The following will be measured at recruitment, after 3-week intervention, after 2-week washout and at the end of the trial i.e. at the end of another 3-week intervention: 1. The self-reported questionnaire containing questions on welfare, nutritional habits, and habitual gastrointestinal symptoms (abdominal pain, flatulence, bloating, and stool frequency) 2. Haematological indices, plasma glucose, total cholesterol (TC), high density lipoprotein (HDL) and low density lipoprotein (LDL) cholesterol, triglyceride and high sensitivity C-reactive protein (hsCRP), Interleukin-6 (IL-6), immunoglobulin levels 3. The content of biogenic amines and polyamines in urine 4. Reverse transcription polymerase chain reaction (RT-PCR) from fecal samples for monitoring the changes in the counts of lactoflora, L. planatrum and survival of the administered strains 5. Denaturing gradient gel electrophoresis (DGGE) used to monitor changes in total fecal microflora after yoghurt consumption
Completion date	20/05/2009

Eligibility

Participant type(s)	Patient
Age group	Adult
Lower age limit	18 Years
Upper age limit	65 Years
Sex	All
Target sample size at registration	60
Key inclusion criteria	1. Wish to participate in the study 2. Both males and females, aged 18-65 years 3. Healthy (i.e. no known health problems and no medical conditions that require drug therapy) 4. Signed informed consent
Key exclusion criteria	1. History of any gastrointestinal disease 2. Use of any antimicrobial agent within the preceding month 3. Use of any regular concomitant medication including non-steroidal anti-inflammatory drugs and antioxidant vitamins 4. Pregnancy or breastfeeding 5. Food allergy 6. Diabetes and acute infections
Date of first enrolment	09/03/2009
Date of final enrolment	20/05/2009

Locations

Countries of recruitment

Estonia

Study participating centre

Tartu Ulikool

Tartu
50411
Estonia

Results and Publications

Individual participant data (IPD) Intention to share	No
IPD sharing plan summary	Not provided at time of registration
IPD sharing plan

Study outputs

Output type	Details	Date created	Date added	Peer reviewed?	Patient-facing?
Participant information sheet	Participant information sheet	11/11/2025	11/11/2025	No	Yes