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NCT Number: NCT05174273

Neurocognitive Effects of FMT in MDD Patients With and Without IBS

This study is a phase 2/3 open-label controlled trial (CT) in which adults with Major Depressive Disorder (MDD) and adults who have MDD plus comorbid Inflammatory Bowel Syndrome (IBS) will be assigned to either receive oral Fecal Microbiota Transplantation (FMT) or to continue with the treatment they are currently receiving in a Treatment As Usual (TAU) arm. An IBS alone group receiving TAU will be recruited as a clinical control group.

The primary goals of this study are to determine effectiveness, safety and tolerability of oral FMT in adults with MDD and in MDD who have comorbid IBS. Additional goals are to characterize patterns and progressions of cognitive and neural correlates associated with MDD and with MDD + IBS and to determine if they improve with FMT. It is known that both, individuals with MDD and those with MDD and IBS show cognitive alterations as well as changes in neural structures, but this study is designed to see if those are changed with treatment response to FMT. Additionally, trial feasibility will be monitored via recruitment rate, study visits adherence and participant retention to inform future trial scalability."

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This study is active but is not currently recruiting participants.

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Key information

Conditions

Major Depressive Disorder Colonic Diseases Colonic Diseases, Functional Depressive Disorder Depressive Disorder, Major Digestive System Diseases Gastrointestinal Diseases Intestinal Diseases Irritable Bowel Syndrome Mental Disorders Mood Disorders

Age range

18 year–60 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 2 / Phase 3

Primary location

University of Calgary, TRW building

Calgary, Alberta, T2N 4Z6, Canada

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Between 18-60 years of age:

Participants should be at least 18 years old and not older than 60 years at the day of screening

  • Have a primary diagnosis of MDD as assessed/confirmed by the M.I.N.I. International Neuropsychiatric Interview (MINI)
  • Have had a well-documented inadequate response to at least 2 approved antidepressants
  • A MADRS score of ≥ 19 at screening and visit 2a
  • Have a comorbid diagnosis of IBS. IBS patients can include any of the following: diarrhea predominant IBS (IBS-D), constipation predominant IBS (IBS-C), IBS with mixed bowel habits (IBS-M), or unclassified with IBS (IBS-U) as confirmed by the referring doctor using ROME III criteria
  • Moderate-to-severe IBS symptoms, as indicated by a score of ≥175 on the IBS Severity Scoring System (IBS-SSS)

Exclusion criteria

  • Participant meets Diagnostic and Statistical Manual of Mental Disorders (DSM-5)[1] Criteria for the following conditions according to the M.I.N.I:
  • Substance Use Disorder within the last 3 months. *(Criteria should include Alcohol and non-alcohol substances except Cannabis)
  • Moderate or severe substance use disorder for Cannabis use the last 3 months
  • Active Anorexia Nervosa or Bulimia nervosa
  • Schizophrenia, schizoaffective or bipolar disorder
  • Active suicidality
  • Regular intake of non-steroidal anti-inflammatory drugs, antibiotics, or iron supplements for medical purposes in the three (3) months prior to study entry
  • Use of prebiotics or probiotics for medical purposes for more than two (2) weeks within the last three (3) months
  • Conditions causing immunosuppression
  • Women who are breastfeeding, pregnant or seeking to get pregnant during the course of this study. Not using an acceptable method of birth control (implants, injectable, combined oral contraceptives, IUDs, sexual abstinence or a vasectomized partner)

Treatment and study plan

Fecal microbiota transplantation

Biological

FMT is a technique in which intestinal microbiota are transferred from a healthy screened donor to a patient, with the goal being to introduce or restore a stable microbial community in the gut.

Other names: FMT

Primary outcomes

  1. The Montgomery-Åsberg Depression Rating Scale (MADRS)

    Time frame: Baseline to week 13

    a 10-item questionnaire which psychiatrists use to measure the severity of depressive episodes in patients with mood disorders. This will be used to evaluate the effectiveness of adjunct oral FMT as compared to TAU with currently accepted approved therapy for MDD.

    The MADRS overall score ranges from 0 to 60. Each item yields a score of 0 to 6 and Higher MADRS score indicates more severe depression

  2. IBS Symptom Severity Scale (IBS-SSS)

    Time frame: Baseline to week 13

    The IBS-SSS is a 5-item questionnaire that is used to assess the severity and frequency of abdominal pain, severity of abdominal distention, dissatisfaction with bowel habits, and interference with quality of life over the past 10 days.

    Scores on the IBS-SSS can range from 0 to 500 with higher scores indicating more severe symptoms. Subjects can be categorized as having mild (75-175), moderate (175-300), or severe (>300) IBS.

Secondary outcomes

  1. Toronto Side Effect Scale (TSES)

    Time frame: Baseline to Week 13

    The TSES is a 32-item instrument that is designed to establish incidence, frequency, and severity of CNS, GI, and sexual side effects. For each side effect, frequency and severity are measured on a 5-point scale. intensity is measured by multiplying frequency and severity.

  2. IBS specific Quality of Life (IBS-QoL)

    Time frame: Baseline to Week 13

    is a self-report 34-item instrument used to assess the impact of IBS and its treatment. used to examine GI tolerability in patients with IBS.

    The individual responses to the 34 items are summed and averaged for a total score and then transformed to a 0-100 scale for ease of interpretation with higher scores indicating better IBS specific quality of life.

  3. nuclear magnetic resonance (NMR) spectrometry

    Time frame: Baseline to Week 13

    To assess the effect of FMT on microbiome profile (community structure and functional metagenome).

Other outcomes

  1. structural and functional neuroimaging

    Time frame: Baseline to week 13

    fMRI to examine brain imaging changes in response to FMT

  2. Number of participants recruited, and completed the study visits

    Time frame: From Baseline to week 13

    trial feasibility will be monitored via recruitment rate, study visits adherence and participant retention to inform future trial scalability

Sponsors and collaborators

Lead sponsor

Valerie Taylor

Other

Registry information

Official study title

Understanding the Neurocognitive Effects of Fecal Microbiota Transplantation in Major Depressive Disorder Patients With and Without Irritable Bowel Syndrome

Important dates

Study start
2022
Primary completion
2024
Study completion
2026
First posted
Dec 30, 2021
Registry last updated
Mar 19, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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