Synbiotic Compound to Reduce Symptoms of Schizophrenia

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

Synbiotic Compound to Reduce Symptoms of Schizophrenia (NCT04226898) is a Phase 2 interventional studying Schizophrenia and Schizoaffective Disorder, sponsored by Sheppard Pratt Health System. RECRUITING as of the most recent ClinicalTrials.gov update. Talk to your doctor before contacting the trial site.

About This Trial

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.

What Stage of Research Is This?

Phase 2 trials evaluate whether a treatment actually works against Schizophrenia and continue monitoring side effects. Phase 2 enrolls larger groups (typically 100–300 patients) and produces the first real efficacy signal. A successful Phase 2 readout is what unlocks the much larger Phase 3 confirmatory trials needed for FDA approval.

This trial is currently recruiting participants. The sponsor has registered the study with ClinicalTrials.gov as actively enrolling, which means new applicants who meet the eligibility criteria can be considered for screening. Trial status can change between updates — confirm current recruiting status with the study contact before traveling for a screening visit.

Target enrollment of 68 participants puts this in the typical range for a Phase 2-style efficacy study or a moderate Phase 3 trial in a focused Schizophrenia subpopulation. At this scale, the study has enough statistical power to detect a clear treatment effect but is not the largest cohort in the field.

Who May Be Eligible (Plain English)

Who May Qualify: - Age 18-65, inclusive. - Capacity for written willing to sign a consent form. - 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. Who Should NOT Join This Trial: - 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 weakened immune system 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. ...See full criteria on ClinicalTrials.gov Always talk to your doctor about whether this trial is right for you.

These are translations of the protocol\'s inclusion and exclusion criteria, simplified for patients and caregivers. The original clinical text appears below. Eligibility is ultimately confirmed by the trial site\'s screening process — this summary is a starting point for a conversation with your doctor, not a final determination.

Original Eligibility Criteria

View original clinical language

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

Treatments Being Tested

BIOLOGICAL

Synbiotic Supplement

Synbiotic supplement 1 powder stick by mouth daily

BIOLOGICAL

Inert Compound

Synbiotic supplement identical placebo 1 powder stick by mouth daily

Locations (1)

Trial sites listed on ClinicalTrials.gov for this study. Site activation status can vary — confirm with the specific site before traveling for a screening visit.

Sheppard Pratt Health System

Batlimore, Maryland, United States

How to Talk to Your Doctor About This Trial

Bring the printable summary of this trial — including the NCT ID (NCT04226898), the sponsor (Sheppard Pratt Health System), and the key eligibility criteria — to your next appointment. Your doctor can review the inclusion and exclusion criteria against your medical history, lab values, and current treatments to assess whether you are likely to qualify. They can also help you weigh whether trial participation makes sense alongside your existing care plan.

Useful questions to walk through together: What does the trial protocol require beyond standard care? How long is the active treatment phase, and how long is follow-up? Are there study visits at sites I can reach? Who pays for the trial-specific procedures, and who pays for standard-of-care portions? See our 25 questions to ask about clinical trials guide for a more complete checklist.

Authoritative Sources

The official record for this trial lives on ClinicalTrials.gov — the federal registry maintained by the National Library of Medicine at NIH. For background on how this trial fits into the FDA approval pathway, see the FDA drug approval process. For oncology-specific guidance for patients considering trials, the National Cancer Institute publishes patient-oriented overviews. International trial registries are aggregated by the WHO ICTRP.

Frequently Asked Questions

What is the NCT04226898 clinical trial studying?

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. The full protocol is registered on ClinicalTrials.gov and includes the primary outcome measures, eligibility criteria, and study endpoints.

Who can participate in NCT04226898?

Eligibility for this trial depends on the specific inclusion and exclusion criteria set by the sponsor. The plain-English summary above translates the most important criteria into accessible language; the official clinical text is preserved in the collapsible section underneath. Whether you fit any specific trial is a medical decision your doctor needs to confirm — bring the trial information to your treating physician for a full review against your medical history.

How do I contact the trial site for NCT04226898?

Contact information registered with ClinicalTrials.gov is shown in the sidebar of this page. Before reaching out, confirm with your treating physician that this trial is appropriate for your situation. The trial site will then walk you through the screening process to determine final eligibility.

Is participating in a clinical trial safe?

Clinical trials in the United States are regulated by the FDA and overseen by Institutional Review Boards (IRBs) that review the protocol for safety. Risk varies by trial — Phase 1 studies test new treatments in humans for the first time, while Phase 3 trials use treatments that have already passed earlier safety screening. The informed consent document for any specific trial details the known risks and what to expect. Discuss those risks with your physician before deciding whether to participate.

Where can I verify the data on this page?

Every detail on this page comes directly from the ClinicalTrials.gov API. Click "View on ClinicalTrials.gov" in the sidebar to see the official, unmodified record. The federal record is always authoritative; this page is a structured presentation with a plain-English eligibility translation. For background on how clinical trials are regulated, see the FDA drug approval process documentation.

How This Page Is Built

Every field on this page is pulled directly from the ClinicalTrials.gov API v2 — no estimates, no proxies. The plain-English eligibility translation is generated from the original protocol text and reviewed for fidelity to the underlying clinical criteria. The original clinical text remains visible in the collapsible section above so users and clinicians can verify the translation. Read the full methodology for the data pipeline and known limitations.

Source: ClinicalTrials.gov API v2 record for NCT04226898. Maintained by the National Library of Medicine at NIH. Public domain. Cite as: "TrialFinderData. NCT04226898. Data: ClinicalTrials.gov."

Medical disclaimer: This page is informational, not medical advice. Talk to your doctor about whether a clinical trial is right for you.

Last updated 2026-06-07 · Data from ClinicalTrials.gov.