ADHD, Gut Problems and Synbiotic

July 16, 2026 updated by: Super Synbiotics AB

Gut-Brain Study: ADHD, Gastrointestinal Problems and Synbiotic Cap

The scope of this study is to evaluate the impact of a synbiotic product (a combination of probiotic bacteria and prebiotics) on symptoms reported by participants with ADHD. The main focus is to study the efficacy of the synbiotic product as compared to a placebo in improving emotion regulation and gut-health associated symptoms in adults with ADHD.

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.
174

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

  • Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • ADHD-diagnosis
  • Self-described gastrointestinal problems
  • Has not previously consumed Synbiotics
  • Be prepared to avoid supplements with lactic acid bacteria, calcium and vitamin B6, B9, and B12, starting from washout

Exclusion Criteria:

  • Has consumed antibiotics within the previous 6 weeks
  • Has a serious disease that requires treatment and/or leads to a weakened immune system

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: Synbiotic Cap Gut-Brain
Capsules containing the synbiotic product being evaluated. The product consists of a combination of probiotic bacteria (at a total dose of 15 x 10^9 CFU/2 capsule), dietary fibers (120 mg), calcium and vitamin B. The participants will be instructed to consume 2 capsules once every day, during a period of 12 weeks.
Dietary supplement: Synbiotic Cap Gut-Brain
Capsules (2 capsules to be ingested once daily during 12 weeks)
Placebo Comparator: Placebo
Capsules containing placebo consisting of maltodextrin. The capsules look, smell and taste the same as the capsules for the experimental product. The participants will be instructed to consume 2 capsules once every day, during a period of 12 weeks.
Other: Placebo
Capsules (2 capsules to be ingested once daily during 12 weeks)

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
Change from baseline in the total score of Difficulties Regulation Scale 16 (DERS-16) after 12 weeks of intervention.
Time Frame: Change from baseline to 12 weeks
All subscales are included in the total score of DERS-16 (Clarity, Goals, Impulse, Strategies and Nonacceptance)
Change from baseline to 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
Change from baseline in total score for gastrointestinal symptoms (based on a questionnaire) after 12 weeks of intervention.
Time Frame: Change from baseline to 12 weeks
The questionnaire consists of a 5-point scale to evaluate the frequency of symptoms such as flatulence, bloating, loose/hard stools, gut pain, feeling sick.
Change from baseline to 12 weeks
Change from baseline in total score of ASRS v1.1 after 12 weeks of intervention
Time Frame: Change from baseline to 12 weeks
The adult ADHD self-report scale consists of 18 items. Change from baseline in the total score for these items will be measured.
Change from baseline to 12 weeks
Change from baseline in the DERS-16 subscale scores after 12 weeks of intervention.
Time Frame: Change from baseline after 12 weeks.
The score for each of the DERS-16 subscales (Clarity, Goals, Impulse, Strategies and Nonacceptance) will be analyzed separately
Change from baseline after 12 weeks.
Change from baseline in the frequency of individual gastrointestinal symptoms after 12 weeks of intervention.
Time Frame: Change from baseline to 12 weeks
The individual gastrointestinal symptoms include flatulence, bloating, loose/hard stools, gut pain, feeling sick.
Change from baseline to 12 weeks
Change from baseline in the score of individual ASRS v1.1 items after 12 weeks of intervention.
Time Frame: Change from baseline to 12 weeks.
The 18 ASRS items will be assessed separately.
Change from baseline to 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.
Super Synbiotics AB

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.
September 1, 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.
October 31, 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.
December 1, 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).
July 16, 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.
July 16, 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.
July 21, 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.
July 21, 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.
July 16, 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.
May 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.
  • Gut-Brain Study

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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