Evaluating the Efficacy of the Mediterranean Diet to the Low- Fermentable, Oligosaccharides, Disaccharides, Monosaccharides, and Polyols (FODMAP) Diet in Treating Irritable Bowel Syndrome(IBS)

March 7, 2025 updated by: Prashant Singh, University of Michigan

Evaluate and Compare the Clinical Efficacy of the Mediterranean Diet to the Low-FODMAP Diet in Treating Irritable Bowel Syndrome

This study is being completed to determine if the Mediterranean (MD) and low FODMAP (fermentable, oligosaccharides, disaccharides, monosaccharides, and polyols) diets are comparable in the effectiveness to treat Irritable Bowel Syndrome (IBS).

The study team hypothesizes that:

  • The low FODMAP and Mediterranean groups will achieve a similar improvement in abdominal pain
  • Both groups will achieve similar improvements in bloating, overall IBS symptom severity, and adequate relief

Study Overview

Status

Status

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

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.

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 (Actual)

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.
26

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.
  • Not Applicable

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

  • United States
    • Michigan
      • Ann Arbor, Michigan, United States, 48109
        • University of Michigan

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

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Patients with IBS-D (diarrhea-predominant IBS) or IBS-M (IBS with mixed subtype) diagnosed per Rome IV questionnaire and without any unexplained alarm features (rectal bleeding, weight loss, nocturnal symptoms, personal history of celiac disease, microscopic colitis, inflammatory bowel disease)
  • Aged 18-70 years at the time of screening
  • Weekly average of worst daily (in the past 24 hours) abdominal pain score of ≥3.0 on a 0-to-10-point scale
  • At least 80 percent compliance in daily questionnaire entries during the 7-day screening period

Exclusion Criteria:

  • Subjects adhering to any dietary IBS treatment such as the low-fodmap diet, or gluten-free diet, Mediterranean currently or within the past 6 months
  • Subjects with a known food allergy to eggs, seafood, peanuts, tree nuts or milk (subjects with lactose intolerance that are experiencing IBS symptoms while on a lactose-free diet will not be excluded from the study).
  • Subjects with a history of poorly controlled insulin-dependent or non-insulin-dependent diabetes
  • Subjects with a known history of organic Gastrointestinal (GI) disease (i.e., celiac disease, inflammatory bowel disease or microscopic colitis)
  • Subjects with a history of an eating disorder requiring medical or behavioral treatment within the past 10 years.
  • Subjects with prior small bowel or colonic surgery (excluding appendectomy or cholecystectomy if over 6 months since these 2 procedures)
  • Oral antibiotic use in the past 3 months
  • Any planned significant changes in dietary or exercise regimen within 30 days prior to Screening or during the study.
  • Currently pregnant or breastfeeding.

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: Double

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: Diet low in all FODMAP groups
Other: Diet low in all FODMAP groups
Randomized participants will eat this diet for 4 weeks (all meals and snacks will be provided). Participants will only eat the study food for this intervention. Participants will be asked to complete surveys, food diaries, and have blood and stools samples pre and post treatment.
Experimental: Diet - Mediterranean
Other: Diet - Mediterranean
Randomized participants will eat this diet for 4 weeks (all meals and snacks will be provided). Participants will only eat the study food for this intervention. Participants will be asked to complete surveys, food diaries, and have blood and stools samples pre and post treatment.

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
Proportion of Participants Who Are Responders Based on the Abdominal Pain Intensity Score for at Least 2 of 4 Weeks
Time Frame: 4 weeks
Results reflect the participants who were weekly responders for at least 2 of the 4 weeks based on their abdominal pain intensity score. The abdominal pain score was a single-question, 11-point numeric rating scale in which 0 represented no abdominal pain and 11 represented the worst possible abdominal pain. Once per day, subjects reported their worst daily (in the past 24 hours) abdominal pain. A weekly responder was defined as a participant whose score decreased in the weekly average of worst abdominal pain in the past 24 hours by at least 30% compared with baseline.
4 weeks

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
Proportion of Participants Who Are Weekly Responders to Adequate Relief Symptom Assessment for at Least 2 of 4 Weeks
Time Frame: 4 weeks
Results reflect the participants who were weekly responders based on the adequate relief symptom assessment for at least 2 of the 4 weeks. Participants provided a binary (yes or no) response to rate the adequacy of relief of global irritable bowel syndrome (IBS) symptoms at the start of the study and weekly thereafter. A weekly responder was defined as a participant who achieved adequate relief in symptoms in at least 2 out of 4 weeks of the treatment period.
4 weeks
Proportion of Participants Who Are Weekly Responders Based on the Irritable Bowel Severity Scoring System (IBS-SSS) Modified Version for at Least 2 of the 4 Weeks
Time Frame: 4 weeks
Results reflect participants who were weekly responders for at least 2 of the 4 weeks based on their scores on a modified version of the IBS-SSS. This version of the IBS-SSS was comprised of 5 questions participants answered based on their stomach and bowels. The total score for this modified version of the IBS-SSS was 0-500, with 0 indicating no IBS symptoms and 500 indicating the highest amount of IBS symptoms. A weekly responder was defined as a participant whose score decreased in the weekly IBS-SSS by at least 50 points compared with baseline.
4 weeks
Change in Mean Score of the Irritable Bowel Severity Scoring System (IBS-SSS) Modified Version
Time Frame: Baseline, 4 weeks
The modified version of the IBS-SSS was comprised of 5 questions participants answered based on their stomach and bowels. The total score for this modified version of the IBS-SSS was 0-500, with 0 indicating no IBS symptoms and 500 indicating the highest amount of IBS symptoms. The results represent the mean change from baseline minus 4 weeks.
Baseline, 4 weeks
Proportion of Participants Who Are Weekly Responders to Bloating for at Least 2 of the 4 Weeks
Time Frame: 4 weeks
Results reflect the number of participants who were weekly responders based on their abdominal bloating score for at least 2 of 4 weeks. The abdominal bloating score was a single-question, 11-point numeric rating scale in which 0 represented no abdominal bloating and 11 represented the worst possible abdominal bloating. Once per day, participants reported their worst daily (in the past 24 hours) abdominal bloating. A weekly responder was defined as a participant whose score decreased in the weekly average of worst bloating in the past 24 hours by at least 30% compared with baseline.
4 weeks
Participants Who Are Weekly Responders to Stool Consistency Based on the Bristol Stool Scale (BSS) for at Least 2 of the 4 Weeks
Time Frame: 4 weeks
Results reflect the participants who were weekly responders based on their stool consistency assessment for at least 2 of 4 weeks. A stool consistency weekly responder was defined as a participant with a 50% or greater reduction in the number of days per week with at least one abnormal stool. Stools that scored as 1 or 2 (hard stool) or 6 or 7 (liquid stool) on the BSS were defined as abnormal.
4 weeks

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.
University of Michigan

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
ModifyHealth

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: Prashant Singh, MD, University of Michigan

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.
April 10, 2023

Primary Completion (Actual)

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.
November 3, 2023

Study Completion (Actual)

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.
November 3, 2023

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).
March 29, 2023

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.
March 29, 2023

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.
April 11, 2023

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.
March 28, 2025

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.
March 7, 2025

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, 2025

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.
  • HUM00227491
  • 5P30DK089503-13 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

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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