The Impact of Probiotics on Sperm Quality in Middle-aged Men

August 4, 2026 updated by: Wecare Probiotics Co., Ltd.

Evaluation of the Effects of Probiotics on Sperm Quality in Middle-aged Men: a Randomized, Double-blind, Placebo-controlled Trial

The clinical trial aims to investigate the impact of probiotic strain BL21 on sperm quality among 46 middle-aged male participants. The primary objective is to validate whether probiotic strain BL21 can effectively improve sperm quality among middle-aged male participants. Initially, participants were instructed to consume the recommended amount of probiotic powder for approximately 8 weeks. At baseline, week 4, and week 8 endpoints, semen analysis, hormone level testing, serum cytokine testing were conducted on the participants, and stool samples were collected from them.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Research has indicated that an increase in male age is independently associated with a reduction in the percentage of motile sperm and sperm with normal morphology, especially in men over 40 years old, potentially linking to a decline in fertility rates. Preclinical studies have shown that supplementation with Long Bifidobacterium can regulate immune responses, inhibit tissue inflammatory factors, and the predictive functions of the gut microbiota suggest an increase in gene abundance within pathways related to secondary metabolite production, antibiotic synthesis, and amino acid biosynthesis in the gut microbiota. To ascertain the effectiveness of the Bifidobacterium BL21 product, a consumer testing experiment was conducted by the investigators to evaluate and gather data on alterations in the gut microbiota of participants prior to and following the use of the product. The trial spanned over 8 weeks, with washout periods incorporated at the commencement and conclusion. Throughout the study, participants ingested Bifidobacterium BL21 and were subjected to a series of health examinations and assessments.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
40

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • China
    • Shangdong
      • Jinan, Shangdong, China, 250012
        • Qilu Hospital of Shangdong University

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  1. Subjects aged 40-59 years old.
  2. Normal levels of gonadotropins, testosterone, and serum prolactin.
  3. No use of other traditional Chinese and Western medicines for oligoasthenoteratozoospermia treatment in the past 3 months.
  4. Patients who can understand the clinical study and commit to complying with the study requirements and procedures.
  5. Patients who have signed the informed consent form and are able to complete the study as per the trial protocol.

Exclusion Criteria:

  1. Organic lesions of the reproductive system;
  2. Use of antibiotics in the two weeks prior to recruitment;
  3. Sexual dysfunctions such as erectile dysfunction, ejaculatory abnormalities, preventing completion of sexual intercourse;
  4. Genitourinary infections, such as Chlamydia or Mycoplasma infections;
  5. Abnormal sex hormone levels;
  6. Obesity (BMI greater than 28);
  7. History of allergies to the probiotic preparations used in this study;
  8. Severe cardiovascular or cerebrovascular diseases, liver or kidney dysfunction, hematologic disorders, psychiatric illnesses, or other severe comorbidities;
  9. Use of medications in the past 3 months that may affect the trial;
  10. According to the investigator's judgment, the subject's condition does not qualify them for participation in the study.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Placebo Comparator: Placebo group
Participants in the placebo group received 3g of maltodextrin per day.
Dietary supplement: Maltodextrin
During the experiment, subjects take one sachet maltodextrin daily with 3.0g. Evaluation is conducted by monitoring the subjects' semen concentration before and after this trial.
Experimental: Probiotic group
Participants in the probiotic group received 1 sachet probiotic product per day.
Dietary supplement: probiotic product
During the experiment, subjects take one sachet probiotic product daily. Evaluation is conducted by monitoring the subjects' semen concentration before and after this trial.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Progressive Sperm Motility Assessed by Computer-Assisted Sperm Analysis
Time Frame: Baseline and week 8
Progressive sperm motility will be assessed using a computer-assisted sperm analysis system (CASA) at baseline and week 8.
Baseline and week 8

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Wecare Probiotics Co., Ltd.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
August 30, 2024

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
May 1, 2025

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
June 1, 2025

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
July 25, 2024

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 5, 2024

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
August 9, 2024

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
August 7, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 4, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
August 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • WK2023010

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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