Microbiome-Targeted Enhancement of Neurocognition With Probiotics-Riboflavin Combination (MENTOR)

February 7, 2026 updated by: Center for Health Sciences, Serbia

Microbiome-Targeted Enhancement of Neurocognition With Probiotics-Riboflavin Combination (MENTOR)

This randomized, double-blind, placebo-controlled trial will evaluate whether 12 weeks of supplementation with the probiotic Lactobacillus rhamnosus GG combined with colon-delivered riboflavin will improve cognitive performance and brain physiology in older adults with memory complaints. The study will assess changes in cognitive outcomes together with neurophysiological markers to explore potential gut-brain axis mechanisms. Through its rigorous design, the trial will aim to determine whether targeted modulation of the intestinal environment can support brain function and cognitive health in aging.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

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.

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 (Estimated)

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.
28

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.

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

  • Older Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Age > 65 years
  • MoCA scores 18-25 points
  • BMI of 20.0 - 29.9 kg/m2 at screening
  • Stable body weight (≤ 5% change) over the past 3-months
  • Willing to avoid consuming gut microbiome-modulating dietary supplements within 4 weeks prior to the baseline visit
  • Subjects will abstain from vitamin B2-rich food intake as per pre-defined list
  • Maintain current level of physical activity
  • Be willing and able to comply with trial protocol

Exclusion Criteria:

  • Severe chronic disease and acute injuries
  • History of dietary supplement use four weeks before enrolment
  • Organic gastrointestinal (GI) disorders
  • Bowel surgery or short bowel syndrome
  • Gut-altering medications two months before enrolment
  • Is currently using systemic steroids, proton pump inhibitors, H2 blocker, antacid
  • History of drug and/or alcohol abuse at the time of enrolment
  • Smoker or vaper
  • Has made any major dietary changes in the past 3 months prior to baseline
  • Has a currently active eating disorder
  • Has food allergies or other issues with foods

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: Supportive Care
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

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.
Experimental: Experimental 1
2 capsules of probiotic and riboflavin cellulose per day
Dietary supplement: Experimental 1
Probiotic and riboflabin
Placebo Comparator: Experimental 2
2 capsules of microcrystaline cellulose per day
Dietary supplement: Experimental 2
Microcrystaline cellulose

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
Montreal Cognitive Assesment scores
Time Frame: Change from baseline The Montreal Cognitive Assessment (MoCA) score at 12 weeks
The Montreal Cognitive Assessment (MoCA) score is a brief, 30-point screening measure of global cognitive function. It assesses multiple domains, including memory, attention, executive function, language, visuospatial abilities, and orientation. Higher scores indicate better cognitive performance, with a score of 26 or above generally considered within the normal range, while lower scores suggest varying degrees of cognitive impairment.
Change from baseline The Montreal Cognitive Assessment (MoCA) score at 12 weeks

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Mini-Mental State Examination Score
Time Frame: Change from baseline Mini-Mental State Examination Score at 12 weeks
The Mini-Mental State Examination score quantifies global cognitive function by assessing orientation, memory, attention, language, and visuospatial abilities, offering a validated measure for detecting cognitive decline in older adults.
Change from baseline Mini-Mental State Examination Score at 12 weeks
Pittsburgh Sleep Quality Index (PSQI)
Time Frame: Change from baseline PSQI at 12 weeks
The Pittsburgh Sleep Quality Index (PSQI) is a self-report tool used to assess sleep quality and disturbances. It consists of 19 items covering seven components: sleep quality, sleep latency, sleep duration, sleep efficiency, sleep disturbances, daytime dysfunction, and use of sleep medications. Each component is scored from 0 to 3, with higher scores indicating worse sleep quality. The total score ranges from 0 to 21, where a score of 5 or higher suggests poor sleep quality. The PSQI is widely used in clinical and research settings to evaluate sleep health.
Change from baseline PSQI at 12 weeks
Brain oxygen saturation
Time Frame: Change from baseline hemoglobin index at 12 weeks
Concentration of hemoglobin index in prefrontal brain
Change from baseline hemoglobin index at 12 weeks
Grip strength
Time Frame: Change from baseline grip strength at 12 weeks
Muscular strength generated by one's forearm muscles
Change from baseline grip strength at 12 weeks

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.
Center for Health Sciences, Serbia

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Nikola Todorovic, PhD, Center for Mitochondrial Medicine

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 (Estimated)

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.
April 15, 2026

Primary Completion (Estimated)

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.
July 15, 2027

Study Completion (Estimated)

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.
August 15, 2027

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).
February 7, 2026

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.
February 7, 2026

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.
February 13, 2026

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.
February 13, 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.
February 7, 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.
February 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.
  • 11-385-28-01

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

Data obtained through this study may be provided to qualified researchers with academic interest in nutritional science. Data will be coded, with no PHI included. Approval of the request and execution of all applicable agreements are prerequisites to the sharing of data with the requesting party.

IPD Sharing Time Frame

Data requests can be submitted starting 9 months after article publication and the data will be made accessible for up to 24 months. Extensions will be considered on a case-by-case basis.

IPD Sharing Access Criteria

Only qualified researchers with academic interest in nutritional science.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP
  • ICF
  • CSR

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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