Anxiety and Depression in IBS: A Brain-Gut Axis Study

June 9, 2026 updated by: songjiajie, Tang-Du Hospital

Investigating the Brain-Gut Axis Regulatory Mechanism of Anxiety and Depression in Irritable Bowel Syndrome

This study aims to understand how the gut and the brain communicate in people with Irritable Bowel Syndrome (IBS) who also experience anxiety and depression. We want to see if changes in gut bacteria are linked to changes in brain function, and to find potential markers that could help in diagnosis or future treatments.

We are looking for two groups of volunteers aged 18 to 60 years: 1) 100 patients diagnosed with IBS who also have symptoms of anxiety or depression, and 2) 100 healthy volunteers for comparison. All participants must be right-handed.

Participants in this observational study will not receive any new drug or treatment. Instead, they will be asked to:

Complete questionnaires about their bowel symptoms, anxiety, depression, sleep, and thinking skills.

Provide a stool sample (about 5 grams) and a blood sample (about 5 ml).

Undergo a brain scan using a 7 Tesla MRI machine, which will take about 45-50 minutes. They will need to lie still during the scan.

Some IBS patients may be invited for a follow-up visit after 3 months to repeat the questionnaires and sample collection.

There are minimal risks involved. The MRI scan is non-radioactive and considered very safe, but some people may feel uncomfortable or claustrophobic inside the machine. Giving blood may cause brief pain, bruising, or, very rarely, infection. Your privacy is protected. All personal information and data will be coded and kept confidential, and will only be used for this research.

The main benefit to participants is receiving a detailed health assessment, including advanced brain imaging and analysis of gut bacteria, at no cost. There is no direct therapeutic benefit from participating, but the knowledge gained may help improve the understanding and future care of IBS.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Study Type

Observational

Enrollment (Estimated)

200

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • China
    • Shaanxi
      • Xi'an, Shaanxi, China, 710038
        • Recruiting
        • Tangdu Hospital, Air Force Medical University
        • Contact:

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

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

Yes

Sampling Method

Non-Probability Sample

Study Population

Adults (18-60 years) with irritable bowel syndrome (IBS) meeting Rome IV criteria and healthy right-handed volunteers, all with at least 6 years of education.

Description

Inclusion Criteria:

  1. Right-handed, aged 18-60 years, with more than 6 years of education;
  2. Meeting the Rome IV diagnostic criteria for IBS: Symptoms have been present for at least 6 months, and for the last 3 months, the following criteria are met: recurrent abdominal pain or discomfort, with symptoms occurring on at least 3 days per month in the last 3 months, associated with two or more of the following: 1) Improvement with defecation; 2) Onset associated with a change in frequency of stool; 3) Onset associated with a change in form (appearance) of stool;
  3. The following symptoms support the diagnosis of IBS: 1) Abnormal stool frequency: <3 bowel movements per week or >3 bowel movements per day; 2) Abnormal stool form: lumpy/hard stool or mushy/watery stool; 3) Straining during defecation; 4) Urgency or a feeling of incomplete evacuation; 5) Passage of mucus; 6) Bloating.

Exclusion Criteria:

  1. History of anti-anxiety/depressant medication use (e.g., SSRI/SNRI, Chinese patent medicines) within the past 1 month;
  2. History of antibiotic or probiotic use within the past 1 month;
  3. Other gastrointestinal diseases such as IBD, intestinal obstruction, or history of gastrointestinal surgery;
  4. Current or past history of psychiatric or neurological disorders, such as psychosis, brain tumors, or impaired consciousness;
  5. Concurrent severe hepatic or renal insufficiency, cardiovascular or cerebrovascular diseases, or malignant tumors; 7.0T MRI Contraindications: Presence of ferromagnetic implants (e.g., cardiac pacemakers, defibrillators, neurostimulators, aneurysm clips, cochlear implants, or any metallic foreign bodies); Non-ferromagnetic implants (e.g., titanium alloy, orthopedic implants), various types of intrauterine devices, various types of non-removable dentures (including dental implants); Presence of metallic foreign bodies (e.g., metal fragments, shrapnel, or filings in the eyes or body), such as in individuals engaged in welding work or with a history of metal item trauma; Tattoos or permanent makeup (e.g., eyebrows, lips) applied within the past month; Claustrophobia; Fever.

HC Group Inclusion Criteria (all must be met):

  1. Right-handed, aged 18-60 years, with more than 6 years of education;
  2. All physiological indicators are within normal ranges, with no signs of disease;
  3. No family history of psychiatric or neurological disorders.

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

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
IBS Patients
Observational Study (No Intervention)
Other: Observational Study (No Intervention)
Observational Study (No Intervention)
Healthy Controls
No Intervention
Other: Observational Study (No Intervention)
Observational Study (No Intervention)

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Alteration in Brain-Gut Axis Functional Connectivity
Time Frame: To assess the change in the severity of irritable bowel syndrome (IBS) symptoms, including abdominal pain, bloating, and bowel habit disturbances, as measured by validated scoring systems (e.g., IBS-SSS) from baseline to the end of the 3-month follow-up
To assess the change in the severity of irritable bowel syndrome (IBS) symptoms, including abdominal pain, bloating, and bowel habit disturbances, as measured by validated scoring systems (e.g., IBS-SSS) from baseline to the end of the 3-month follow-up

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Tang-Du Hospital

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)

December 21, 2025

Primary Completion (Estimated)

December 21, 2026

Study Completion (Estimated)

December 30, 2027

Study Registration Dates

First Submitted

June 9, 2026

First Submitted That Met QC Criteria

June 9, 2026

First Posted (Actual)

June 15, 2026

Study Record Updates

Last Update Posted (Actual)

June 15, 2026

Last Update Submitted That Met QC Criteria

June 9, 2026

Last Verified

June 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • K202512-21

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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