Investigation of Pathogenic Gut Microbiota Patterns in Anxiety, Depression and Panic Disorders

NCT07268729 | Completed DMC

• 1 other identifier: Pro00084759
• Study Type: observational
• Target: 500
• Locations: 1 country
• Sites: 1

Brief Summary

This study aims to investigate the etiology of anxiety, depression, and panic disorders, providing new evidence and insights into the root causes and effective treatments, potentially offering a novel approach to achieving complete recovery.

Conditions

Anxiety; Panic Disorder; Mood Disorders; Depression

Outcome Measures

Primary Outcomes (1)

• Presence of pathogenic gut bacteria

  The presence of pathogenic bacterial species will be identified through microbiome sequencing of stool samples using a validated laboratory assay. Sequencing data will be analyzed to detect and quantify bacterial taxa associated with dysbiosis and pathogenicity within the gut microbiome. The primary outcome will be defined as the detection of one or more bacterial pathogens meeting pre-specified taxonomic or functional criteria.

  Day 10 Upon receipt of stool analysis results

Secondary Outcomes (1)

• Symptom reduction, and eradication.

  Day 0 (baseline), Day 24 (post-eradication reassessment), and Day 30 (post-eradication reassessment)

Study Arms (3)

Patients under ongoing treatment

Participants in this group are adults currently receiving ongoing treatment for anxiety, depression, or panic disorder. Treatment may include prescribed medication, psychotherapy, or other clinician-supervised care. These participants will complete the same baseline psychological assessments and stool microbiome testing as the other cohorts. Their data will help evaluate how existing treatments may influence gut microbiome composition and mental-health outcomes over time.

Diagnostic Test: H pylori stool test; Diagnostic Test: Bacterial stool analysis

Healthy controls with no psychiatric history

Participants in this group are healthy adults with no self-reported or clinically diagnosed history of psychiatric or neurological disorders. They will complete the same baseline assessments and biological sample collection (including stool microbiome testing) as the clinical cohort, but will not receive any treatment or individualized intervention. Their data will serve as a comparison reference to help identify microbiome and biomarker patterns associated with anxiety and depression.

Diagnostic Test: H pylori stool test; Diagnostic Test: Bacterial stool analysis

Patients with clinically confirmed anxiety, depression, and panic disorder.

Participants in this cohort are adults with a current, clinically confirmed diagnosis of anxiety disorder, depressive disorder, or panic disorder. Each participant will provide baseline psychological assessments and biological samples, including stool microbiome testing. Based on their results, they may receive individualized lifestyle or dietary recommendations under physician supervision. Participants will be followed over time to evaluate changes in mood, stress, and biological markers related to mental-health outcomes.

Diagnostic Test: H pylori stool test; Diagnostic Test: Bacterial stool analysis

Interventions

H pylori stool test DIAGNOSTIC_TEST

Participants will provide a stool sample for noninvasive testing to detect the presence of Helicobacter pylori bacteria. The test will be performed using a validated laboratory assay that identifies H. pylori antigens in stool. Results will be used to assess potential associations between H. pylori infection, gut microbiome composition, and symptoms of anxiety or depression. The test is diagnostic only and does not involve administration of any drug or treatment.

Healthy controls with no psychiatric history; Patients under ongoing treatment; Patients with clinically confirmed anxiety, depression, and panic disorder.

Bacterial stool analysis DIAGNOSTIC_TEST

Participants will provide stool samples for microbiome sequencing using a validated laboratory assay. The analysis will characterize bacterial taxa within the gut microbiome and identify potential pathogenic species. Sequencing results will be correlated with psychological assessments and clinical measures to investigate relationships between gut microbial composition and symptoms of anxiety, depression, and panic disorder.

Healthy controls with no psychiatric history; Patients under ongoing treatment; Patients with clinically confirmed anxiety, depression, and panic disorder.

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

The study population will consist of adult males and females aged 18 to 65 recruited from the general population and outpatient mental health clinics. Participants will include individuals with clinically confirmed anxiety, depression, or panic disorder, as well as healthy control subjects with no psychiatric history. The study will aim to include participants from diverse ethnic and cultural backgrounds to ensure broad representation of the population.

You may qualify if:

• Adults aged 18-65 years.
• Either of the following:
• Diagnosed with anxiety, depression, or panic disorder according to DSM-5 criteria, regardless of current treatment status.
• Healthy individuals with no history of psychiatric disorders (control group).
• Able to provide informed consent and stool sample.

You may not qualify if:

• Diagnosis of psychotic disorders or neurocognitive conditions.
• Use of systemic antibiotics or antifungals within the past 60 days.

Sponsors & Collaborators

• University of Toronto: lead
• MedBliss Research Network: collaborator

Study Sites (1)

MedBliss Research Network

Mississauga, Ontario, L5B3C2, Canada

Location

MeSH Terms

Conditions

Anxiety Disorders; Panic Disorder; Mood Disorders; Depression

Condition Hierarchy (Ancestors)

Mental Disorders; Behavioral Symptoms; Behavior

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Study Record Dates

• First Submitted: November 18, 2025
• First Posted: December 8, 2025
• Study Start: December 10, 2025
• Primary Completion: January 25, 2026
• Study Completion: February 10, 2026
• Last Updated: April 29, 2026

Record last verified: 2026-04

Data Sharing

• IPD Sharing: Will not share

Locations

CA (1)