Probiotics for men

ISRCTN	ISRCTN54942056
DOI	https://doi.org/10.1186/ISRCTN54942056

Submission date: 03/07/2023
Registration date: 06/07/2023
Last edited: 20/01/2025

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

Prospectively registered

Protocol

Statistical analysis plan

Results

Individual participant data

Plain English Summary

Background and study aims
The microbiota of the male genital tract plays an important role in men's health. It affects semen quality and prostate health. Prostatitis syndrome is associated with microbiota imbalance in the male genital organs. Various animal experiments have proven that probiotics can improve sperm quality or influence testosterone levels. Scarce studies have shown a beneficial effect of probiotics in the case of prostatitis. The study team developed a probiotic mixture for prostatitis patients using laboratory experiments. As a next step, the safety and tolerability of this novel probiotic mixture will be tested in healthy volunteers.

Who can participate?
Healthy volunteer men aged between 18-65 years old

What does the study involve?
Study participants consume 1 oral capsule per day containing four lactobacilli strains (daily dose 10E9 CFU) for one week. Blood markers are recorded at the beginning and at the end of the study. The participants fill out a daily questionnaire during the consumption period about their health and well-being.

What are the possible benefits and risks of participating?
A possible benefit is proving the safety of potential probiotics in healthy men. Possible risks are low since the European Food Safety Association (EFSA) has placed lactobacilli on the qualified presumption of safety (QPS) list. In addition, the study team tested several safety markers in the lactobacilli strains in the laboratory.

Where is the study run from?
University of Tartu (Estonia)

When is the study starting and how long is it expected to run for?
December 2020 to December 2022

Who is funding the study?
Competence Centre on Health Technologies (Estonia)

Who is the main contact?
Dr Reet Mändar, reet.mandar@ut.ee (Estonia)

Contact information

Prof Reet Mändar
Principal Investigator

University of Tartu
Ravila 19
Tartu
50411
Estonia

ORCID ID	0000-0002-9747-3618
Phone	+372 7 374 179
Email	reet.mandar@ut.ee

Dr Kristo Ausmees
Scientific

Medita clinic in Tartu
Teguri 37b
Tartu
50107
Estonia

Phone	+372 52 17501
Email	kristo.ausmees@medita.ee

Ms Imbi Smidt MSc
Public

University of Tartu
Ravila 19
Tartu
50411
Estonia

Phone	+372 7 374 178
Email	imbi.smidt@ut.ee

Study information

Study design	Interventional non-randomized study
Primary study design	Interventional
Secondary study design	Non randomised study
Study setting(s)	Other therapist office
Study type	Safety
Participant information sheet	43887_PIS.pdf
Scientific title	Safety of potential probiotics in healthy male volunteers
Study hypothesis	Novel probiotic mixture is safe and well tolerable during oral consumption.
Ethics approval(s)	Approved 19/09/2022, Research Ethics Committee of the University of Tartu (Raekoja plats 9, Tartu, 51004, Estonia; +372 737 6215; eetikakomitee@ut.ee), ref: 368/M-5
Condition	Safety of potential probiotics in healthy male volunteers
Intervention	Healthy volunteer men aged 18-65 without health complaints are recruited. The research material is probiotic capsules used as a food supplement, which contain 4 different strains of lactobacilli with a total germ count of 10E9 microbial cells. Probiotic bacteria are lyophilized and packaged in capsules. Based on in vitro tests, the strains selected for the study prevent the growth of bacteria associated with genitourinary tract infections, and their antibiotic sensitivity profile meets the requirements of the European Food Safety Authority. Study participants consume 1 capsule per day (daily dose of probiotic microbe: 10E9 CFU) for one week. Blood markers (haemoglobin (g/L), haematocrit (%), WBC (10E9/L), RBC (10E12 /L), platelets (10E9/L), neutrophils (10E9/L), eosinophils (10E9/L), basophils (10E9/L), monocytes (10E9/L), lymphocytes (10E9/L), Ig (%), CRP (mg/L), HbA1c (mmol/mol), glucose (mmol/L), cholesterol (mmol/L), LDL (mmol/L), HDL (mmol/L), GGT (U/L), ALAT (U/L), ASAT (U/L), creatinin (µmol/L), EGFR (mL/min/1,73m2), estradiol (pmol/L), testosterone (nmol/L), SHBG (nmol/L), FAI (%), and PSA (µg/L)) are recorded at the beginning and at the end of the study. The participants fill out a short daily questionnaire during the consumption period about their health and well-being.
Intervention type	Supplement
Primary outcome measure	Safety and tolerability of the probiotic capsules measured using a bespoke daily questionnaire at baseline and one week at the end of the study
Secondary outcome measures	Levels of blood markers measured using blood analysis and general health conditions measured using a questionnaire are assessed before and at the end of the study (one week later)
Overall study start date	02/12/2020
Overall study end date	31/12/2022

Eligibility

Participant type(s)	Healthy volunteer
Age group	Adult
Lower age limit	18 Years
Upper age limit	65 Years
Sex	Male
Target number of participants	10
Total final enrolment	10
Participant inclusion criteria	Healthy volunteer men aged 18-65 years without health complaints
Participant exclusion criteria	1. Inflammation of the urogenital tract 2. Diabetes 3. Acute/chronic (infectious) disease 4. Cardiovascular disease 5. Food allergy 6. Use of antibiotics within 4 weeks before the study 7. Regular use of NSAID 8. Blood donation within the last month
Recruitment start date	22/09/2022
Recruitment end date	20/12/2022

Locations

Countries of recruitment

Estonia

Study participating centre

MediTA Clinic

Teguri 37b
Tartu
51013
Estonia

Sponsor information

Competence Centre on Health Technologies (Estonia)
Research organisation

Teaduspargi 13
Tartu
EE50411
Estonia

Phone	+372 733 0401
Email	reetm@ut.ee
Website	http://www.ccht.ee
"ROR"	https://ror.org/05kagrs11

Funders

Funder type

Research organisation

Competence Centre on Health Technologies (CCHT)

No information available

Results and Publications

Intention to publish date	31/12/2023
Individual participant data (IPD) Intention to share	Yes
IPD sharing plan summary	Available on request
Publication and dissemination plan	Planned publication in a high-impact peer-reviewed journal
IPD sharing plan	The datasets generated during the study will be available upon reasonable request from Dr Reet Mändar, reet.mandar@ut.ee

Study outputs

Output type	Details	Date created	Date added	Peer reviewed?	Patient-facing?
Other files	Safety investigation of potential probiotics in healthy volunteers in men		05/07/2023	No	No
Participant information sheet	Subject information and informed consent form [Estonian]		05/07/2023	No	Yes
Results article		04/01/2025	20/01/2025	Yes	No

Additional files

43887_questionnaire.pdf: Safety investigation of potential probiotics in healthy volunteers in men
43887_PIS.pdf: Subject information and informed consent form [Estonian]

Editorial Notes

20/01/2025: Publication reference added.
05/07/2023: Trial's existence confirmed by the Human Research Ethics Committee of the University of Tartu (Estonia).