Synbiotic Compound to Reduce Symptoms of Schizophrenia

April 1, 2026 updated by: Faith Dickerson, Sheppard Pratt Health System

A Double-Blind Placebo-Controlled Trial of the Synbiotic Compound Probio-Tec ABCG for Schizophrenia Patients With and Without Elevated Markers of Gastrointestinal Inflammation

The purpose of this study is to determine if taking a synbiotic supplement versus a placebo will reduce symptoms of schizophrenia when used in addition to standard antipsychotic medications.

Study Overview

Status

Status

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

Detailed Description

A total of n=68 participants with schizophrenia or schizoaffective disorder who have residual psychotic symptoms which are of at least moderate severity will be randomized. Intestinal inflammation will be assessed through the measurement of antibodies to Saccharomyces cerevisiae, gliadin, Candida albicans as well as high-sensitivity C-Reactive protein and Pentraxin-3. The duration of the trial is 14 weeks: after a 2-week placebo run in, the participants will be randomized to receive the synbiotic compound or identical-appearing placebo over the 12 weeks of the randomized phase. The synbiotic compound is a quality-tested product, Probio-Tec ABCG-Stick-25, manufactured by ChrHansen which contains 4 strains of probiotic microorganisms - Bifidobacteria BB-12, Lactobacillus casei, Lactobacillus acidophilus, and Lactobacillus rhamnosus - and the prebiotic, inulin, a fructan-containing polysaccharide which has been shown to increase the level of non-pathogenic bacteria in the gastrointestinal tract. All participants will also be maintained on a stable regimen of psychiatric medications prescribed by their treating psychiatrist.

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.
68

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.
  • Phase 2

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

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

14 years to 61 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Age 18-65, inclusive.
  • Capacity for written informed consent.
  • Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5) diagnosis of schizophrenia or schizoaffective disorder (APA 2013) as determined by the Structured Clinical Interview for DSM-5 Disorders (SCID-5).
  • Outpatient at the time of enrollment.
  • Residual psychotic symptoms of at least moderate severity as evidenced by a Positive and Negative Syndrome Scale (Kay et al., 1987) (PANSS) total score of 60 or higher AND one or more of the following: one or more PANSS positive symptom scores of 4 or higher; OR containing at least three positive or negative items with scores of 3 or higher at the screening visit.
  • Receiving antipsychotic medication for at least 8 weeks prior to starting the study with no medication changes within the previous 21 days.
  • Proficient in the English language.

Exclusion Criteria:

  • DSM-5 diagnosis of intellectual disability or comparable diagnosis determined by previous versions of the DSM.
  • Any clinically significant or unstable medical disorder as determined by the investigators, including congestive heart failure, liver disease, renal failure, any diagnosis of cancer undergoing active treatment.
  • A primary immunodeficiency condition such as HIV infection, or undergoing cancer chemotherapy, or receiving systemic corticosteroids, methotrexate or monoclonal antibodies for treatment of an autoimmune disorder.
  • History of IV drug use.
  • DSM-5 diagnosis of a moderate or severe substance use disorder, except for caffeine or tobacco, within the last three months prior to the screening visit. If the patient has a positive drug toxicity screen at the time of visit 1 (screening) further evaluation by the investigator will be done of the substance use to determine eligibility.
  • Participated in any investigational drug trial in the past 30 days.
  • Pregnant or planning to become pregnant during the study period.
  • Receipt of antibiotic medication within the 14 days prior to visit 2 (as anaerobic organisms residing in the gastrointestinal tract may be minimally affected by antibiotics). Of note, patients on antibiotic may be re-screened once the minimum duration of time since antibiotics use has been met.
  • Current and regular use of a probiotic and or prebiotic supplement within the past 2 weeks. Of note, patients taking prebiotic or probiotic supplements may be re-screened.
  • Documented inflammatory bowel disease (e.g. Crohn's disease or ulcerative colitis) or celiac disease

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: 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 Supplement
The active synbiotic supplement consists of a stick/packet containing 4 strains of probiotic microorganisms: Lactobacillus acidophilus, LA-5® (material number 501082 FD LAK KGPharma); Lactobacillis paracasei subsp. paracasei, L. CASEI 431® (material number 684301 FD L. casei 431 HA Granulate); Lactobacillus rhamnosus, LGG® (material number 699817 FD LGG HA-W-IF); and Bifidobacterium animalis subsp. lactis, BB-12® (material number 699813 FD BB-12 HA-W-IF). In addition, the stick/sachet contains 5 g inulin. The product is a powder which participants will be asked to take with liquid or food. In this arm, the participant will take 1 powder stick of the synbiotic supplement once a day for 12 weeks after a 2-week placebo run-in.
Biological: Synbiotic Supplement
Synbiotic supplement 1 powder stick by mouth daily
Other Names:
  • Probio-Tec® ABCG-Stick-25
Placebo Comparator: Inert Compound
The inert compound placebo looks identical to the synbiotic supplement. In this arm, the participant will take 1 powder stick of the placebo daily for 12 weeks after a 2 week placebo run-in.
Biological: Inert Compound
Synbiotic supplement identical placebo 1 powder stick by mouth daily

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 in Positive and Negative Syndrome Scale (PANSS) Score From the Start to the End of the Double-blind Treatment Phase
Time Frame: 12 weeks (week 2 to week 14)
The Positive and Negative Syndrome Scale (PANSS) measures psychiatric symptomatology, especially related to psychosis. The complete PANSS contains ratings for 30 symptoms, including 7 positive symptoms, 7 negative symptoms, and 16 general psychiatric symptoms. The severity of each symptom is rated on a scale ranging from 1 (minimal) to 7 (extreme); higher scores indicate increased symptomatology. Total PANSS scores include scores from all categories and range from 30 to 210 units on a scale.
12 weeks (week 2 to week 14)

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 in the Measurement and Treatment Research to Improve Cognition in Schizophrenia (MATRICS) Consensus Cognitive Battery (MCCB) score from the start of the placebo run-in to the end of the double-blind phase
Time Frame: 14 weeks (week 0 to week 14)
Cognitive performance is measured by the MATRICS Consensus Cognitive Battery composite score in participants. MCCB is comprised of 10 tests: Trail Making Test Part A; Brief Assessment in Cognition in Schizophrenia Symbol Coding; Hopkins Verbal Learning Test-Revised; Wechsler Memory Scale-III Spatial Span; Letter Number Sequencing; Neuropsychological Assessment Battery Mazes; Brief Visuospatial Memory Test-Revised; Category Fluency Animal Naming; Mayer-Salovey-Caruso Emotional Intelligence Test Managing Emotions; and Continuous Performance Test-Identical Pairs. For each test, a score is derived based on the raw item values. Each of the individual item raw scores is standardized to age and gender corrected tscores which are then summed to convert into a composite score ranging from <214->486 based on the MCCB scoring manual, with a higher score reflecting better performance.
14 weeks (week 0 to week 14)
Intestinal Inflammation Markers (#1) Antibodies to Saccharomyces cerevisiae
Time Frame: Screening, Week 8, Week 14
Levels of intestinal inflammation will be assessed by the measurement of antibodies by immunoassays to Saccharomyces cerevisiae. (All of the immunoassays will be analyzed on the same scale. This is accomplished by standardizing the optical density values obtained from the immunoassays to those of a control population without a psychiatric disorder normalized to have a mean value of 1 and a standard deviation of 1. To adjust for multiple comparisons in the analysis of the 5 markers, the false discovery correction of Benjamani-Hochberg will be used.)
Screening, Week 8, Week 14
Intestinal Inflammation Markers (#2) Antibodies to Gliadin
Time Frame: Screening, Week 8, Week 14
Levels of intestinal inflammation will be assessed by the measurement of antibodies by immunoassays to gliadin. (All of the immuoassays will be analyzed on the same scale. This is accomplished by standardizing the optical density values obtained from the immunoassays to those of a control population without a psychiatric disorder normalized to have a mean value of 1 and a standard deviation of 1. To adjust for multiple comparisons in the analysis of the 5 markers, the false discovery correction of Benjamani-Hochberg will be used.)
Screening, Week 8, Week 14
Intestinal Inflammation Markers (#3) Antibodies to Candida albicans
Time Frame: Screening, Week 8, Week 14
Levels of intestinal inflammation will be assessed by the measurement of antibodies by immunoassays to Candida albicans. (All of the immunoassays will be analyzed on the same scale. This is accomplished by standardizing the optical density values obtained from the immunoassays to those of a control population without a psychiatric disorder normalized to have a mean value of 1 and a standard deviation of 1. To adjust for multiple comparisons in the analysis of the 5 markers, the false discovery correction of Benjamani-Hochberg will be used.)
Screening, Week 8, Week 14
Intestinal Inflammation Markers (#4) C-reactive protein
Time Frame: Screening, Week 8, Week 14
Levels of intestinal inflammation will be assessed by the measurement of high-sensitivity C-reactive protein. (All of the immunoassays will be analyzed on the same scale. This is accomplished by standardizing the optical density values obtained from the immunoassays to those of a control population without a psychiatric disorder normalized to have a mean value of 1 and a standard deviation of 1. To adjust for multiple comparisons in the analysis of the 5 markers, the false discovery correction of Benjamani-Hochberg will b used.)
Screening, Week 8, Week 14
Intestinal Inflammation Markers (#5) Pentraxin-3
Time Frame: Screening, Week 8, Week 14
Levels of intestinal inflammation will be assessed by the measurement of Pentraxin-3. (All of the immunoassays will be analyzed on the same scale. This is accomplished by standardizing the optical density values obtained from the immunoassays to those of a control population without a psychiatric disorder normalized to have a mean value of 1 and a standard deviation of 1. To adjust for multiple comparisons in the analysis of the 5 markers, the false discovery correction of Benjamani-Hochberg will be used.)
Screening, Week 8, Week 14

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.
Sheppard Pratt Health System

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: Faith Dickerson, PhD, MPH, Sheppard Pratt Health System

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.
February 21, 2022

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.
March 1, 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).
January 3, 2020

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.
January 9, 2020

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.
January 13, 2020

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.
April 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.
April 1, 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.
March 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.
  • SMRI/SPHS: 2020-01

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

Demographic, symptom, and cognitive data will be shared with the National Database for Clinical Trials Related to Mental Illness (NDCT). Access may be obtained through an approved application with the NDCT.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

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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