Irritable Bowel SyndromeNMIBS_MedDietNCT07901972
Nutritional Management of the Irritable Bowel Syndrome(IBS): The Role of the Mediterranean Diet (MD)
A study testing Mediterranean Standard Diet and Mediterranean Modified Low FODMAP Diet in people with Irritable Bowel Syndrome, run by University Hospital of Patras.
Trial summary
Irritable Bowel Syndrome (IBS) is a common gastrointestinal disorder with a significant impact on the quality of life of patients. Its global prevalence varies considerably, estimated at up to 10%, due to differences in diagnostic criteria, cultural factors and dietary patterns. Read more about this study
- Who is it for?
- Ages 18 to 65 years
- Conditions the study is for
- Irritable Bowel Syndrome
- What is being tested?
- Mediterranean Standard Diet and Mediterranean Modified Low FODMAP Diet
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 108 participants
- Where
- No sites listed yet
- Study dates
- Oct 2026to Dec 2029
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 65 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Diagnosis of IBS according to the Rome V criteria (IBS-C, IBS-D, IBS-U, IBS-M)
- Age 18-65 years
- Provision of written informed consent
- Caucasian ethnicity
Who cannot join
- Any comorbid condition requiring a specialized or medically restricted diet, such as renal failure, diabetes mellitus, celiac disease, cerebrovascular disorders of the central nervous system, food allergies, or a history of major abdominal surgery
- Εating disorders
- Recent use of antibiotics or probiotics within 1 month before the intervention
- Current hypnotherapy
- Pregnancy
- Breastfeeding
Trial locations and contacts
No sites are listed yet. Contact the study team or a site near you to ask about taking part.
About this study
Irritable Bowel Syndrome (IBS) is a common gastrointestinal disorder with a significant impact on the quality of life of patients. Its global prevalence varies considerably, estimated at up to 10%, due to differences in diagnostic criteria, cultural factors and dietary patterns. Dietary interventions have emerged as first-line strategies for symptom management, with the low Fermentable Oligo-, Di-, and Monosaccharides and Polyols (FODMAP) diet demonstrating strong efficacy in reducing gastrointestinal symptoms by minimizing poorly absorbed, fermentable carbohydrates. However, concerns about long-term nutritional adequacy, potential alterations in gut microbiota composition, and sustainability of the low-FODMAP diet have led to the need for more comprehensive and nutritionally balanced dietary models.
In contrast, the Mediterranean Diet (MD), is widely recognized for its anti-inflammatory, cardiometabolic, and potential anticancer effects. Notably, adherence to the MD has been associated with favorable gut microbial profiles and a reduced risk of colorectal and other gastrointestinal cancers. However, the high FODMAP content of many components of the MD may limit its direct compatibility with dietary protocols for IBS. Incorporating the principles of the MD into a low-FODMAP dietary approach offers a promising strategy for enhancing the nutritional quality, sustainability, and long-term effectiveness of dietary management in IBS.
The aim of the study is to investigate and compare the effectiveness of a Mediterranean Modified Low FODMAP diet (Med-Mod LFD) with standard Mediterranean dietary recommendations (Med standard) in managing the symptoms of IBS. Specifically, the study aims to evaluate the impact of the two dietary interventions on the frequency and severity of gastrointestinal symptoms, to examine potential differences in quality of life, to assess patient compliance and acceptance of the two dietary approaches, and to explore whether the Med-Mod Low FODMAP variation of the Mediterranean diet offers advantages over the classical Mediterranean diet without compromising the health-promoting characteristics that make it beneficial.Dietary intake will also be assessed using a three-day food diary, which will be used for the dietary analysis of participants' food intake and for the assessment of macro- and micronutrient intake of the two dietary interventions
- Conditions
- Irritable Bowel Syndrome
- Being tested
- Mediterranean Standard Diet, Mediterranean Modified Low FODMAP Diet
- Keywords
- Low FODMAP diet, Mediterranean diet, Irritable Bowel Syndrome, IBS
- Medical subject headings
- Irritable Bowel Syndrome
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Mediterranean Standard DietOther
Mediterranean diet recommendations for a period of 6 weeks
Mediterranean Modified Low FODMAP DietOther
Mediterranean-modified low-FODMAP dietary program, including elimination, reintroduction and personalization/maintenance phases
| Study group | Role | What they receive |
|---|---|---|
| Mediterranean Standard Diet | Active comparator | All participants in this group will be instructed to follow Mediterranean diet recommendations, based on the Greek National Dietary Guidelines, for the management of Irritable Bowel Syndrome for a period of 6 weeks. Receives: Other: Mediterranean Standard Diet |
| Mediterranean Modified Low FODMAP Diet | Experimental | All participants in this group will initially follow the Mediterranean Modified Low FODMAP Diet during Phase 1 (the elimination phase) for 6 weeks. During Phase 2 (the reintroduction phase), patients will gradually reintroduce foods high in FODMAPs over a period of 6-8 weeks and assess their individual tolerance. During Phase 3 (the maintenance phase), following the reintroduction of high-FODMAP foods, patients will follow an individualized diet based on their personal tolerance, combining high- and low-FODMAP foods. Receives: Other: Mediterranean Modified Low FODMAP Diet |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in symptom severity from baseline to post-intervention, assessed using a validated disease-specific questionnaire.
The Irritable Bowel Syndrome Severity Scoring System (IBS-SSS) consists of five items, each accompanied by specific scoring instructions. The five items assess pain severity, pain frequency, severity of abdominal distension, satisfaction with bowel habits, and the impact of IBS on quality of life. Each item is scored from 0 to 100 using a visual analogue scale (VAS), yielding a total score ranging from 0 to 500, with higher scores indicating greater symptom severity. Patients may be classified as having mild (75-175), moderate (175-300), or severe (>300) IBS. A reduction of 50 points is considered clinically meaningful.
Measured: Baseline, 6 Weeks and 6 months
Secondary outcomes (4)
Assessment of IBS-related quality of life using a disease-specific questionnaire before and after the intervention, with comparisons between the study groups.
The Irritable Bowel Syndrome Quality of Life (IBS-QOL) is a self-reported, disease-specific measure that assesses the extent to which IBS has affected patients' quality of life during the previous 30 days. It includes eight domains: dysphoria, interference with activity, body image, health worry, food avoidance, social reactions, sexual concerns, and relationships. Each item is rated on a 5-point Likert scale, with higher scores indicating poorer quality of life. The total raw score ranges from 34 to 170. A reduction of at least 10 points is considered a clinically meaningful improvement.
Measured: Baseline, 6 weeks and 6 months
Bristol Stool Form Scale (BSFS), Type 1-7
Stool consistency will be assessed using the Bristol Stool Form Scale, a 7-point categorical scale ranging from Type 1 (separate hard lumps) to Type 7 (watery stool with no solid pieces). Higher scores indicate progressively softer and looser stool consistency. Because both ends of the scale represent abnormal consistency - Types 1-2 indicating hard stool/constipation and Types 6-7 indicating loose/watery stool/diarrhea - the scale is not unidirectional, and neither a higher nor a lower score represents a uniformly better or worse outcome. Types 3-4 represent normal stool consistency and are generally considered the optimal range.
Measured: baseline, 6 weeks and 6 months
Assessment of anxiety and depressive symptoms before and after the intervention.
The Hospital Anxiety and Depression Scale (HADS) is used to assess symptoms of anxiety and depression. It comprises 14 items divided into two seven-item subscales: anxiety (HADS-A) and depression (HADS-D). Each item is rated on a 4-point response scale ranging from 0 to 3. The score for each subscale is calculated by summing the corresponding seven items and ranges from 0 to 21. A score of 0-7 indicates no clinically relevant symptoms, 8-10 indicates mild symptoms, and a score of ≥11 indicates more severe symptoms of anxiety or depression.
Measured: Baseline, 6 weeks and 6 months
Mediterranean Diet Adherence Score
The Mediterranean Diet Adherence Screener (MEDAS) is a 14-item questionnaire used to assess adherence to the Mediterranean diet. The items evaluate the consumption of key components of the Mediterranean dietary pattern, including whole grains, fruits, vegetables, legumes, fish, meat and meat products, poultry, full-fat dairy products, sweets, olive oil, and alcohol. The total MEDAS score ranges from 0 to 14, with higher scores indicating greater adherence. Adherence is classified as low (≤5), moderate (6-9), or high (≥10).
Measured: Baseline, 6 weeks and 6 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted28 Oct 2026
- Study startOct 2026 (estimated)
- Primary completionDec 2029 (estimated)
- Study completionDec 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Irritable Bowel SyndromeStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 108 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University Hospital of Patras
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Christos Triantos, University of Patras
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07901972
- Sponsor's protocol ID
- 189/04.05.2026
- Acronym
- NMIBS_MedDiet
- Status last verified
- Aug 2026
- First submitted
- 12 Aug 2026
- Last updated
- 28 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 28 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Nutritional Management of the Irritable Bowel Syndrome(IBS): The Role of the Mediterranean Diet (MD)
- ClinicalTrials.gov ID
- NCT07901972
- Acronym / sponsor ID
- NMIBS_MedDiet / 189/04.05.2026
- Conditions
- Irritable Bowel Syndrome
- Keywords
- Low FODMAP diet, Mediterranean diet, Irritable Bowel Syndrome, IBS
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 108 participants (estimated)
- Lead sponsor
- University Hospital of PatrasUniversity, hospital or other
- Study start
- Oct 2026 (estimated)
- Primary completion
- Dec 2029 (estimated)
- Study completion
- Dec 2029 (estimated)
- First posted
- 28 Oct 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Irritable Bowel Syndrome (IBS) is a common gastrointestinal disorder with a significant impact on the quality of life of patients. Its global prevalence varies considerably, estimated at up to 10%, due to differences in diagnostic criteria, cultural factors and dietary patterns. Dietary interventions have emerged as first-line strategies for symptom management, with the low Fermentable Oligo-, Di-, and Monosaccharides and Polyols (FODMAP) diet demonstrating strong efficacy in reducing gastrointestinal symptoms by minimizing poorly absorbed, fermentable carbohydrates. However, concerns about long-term nutritional adequacy, potential alterations in gut microbiota composition, and sustainability of the low-FODMAP diet have led to the need for more comprehensive and nutritionally balanced dietary models.
In contrast, the Mediterranean Diet (MD), is widely recognized for its anti-inflammatory, cardiometabolic, and potential anticancer effects. Notably, adherence to the MD has been associated with favorable gut microbial profiles and a reduced risk of colorectal and other gastrointestinal cancers. However, the high FODMAP content of many components of the MD may limit its direct compatibility with dietary protocols for IBS. Incorporating the principles of the MD into a low-FODMAP dietary approach offers a promising strategy for enhancing the nutritional quality, sustainability, and long-term effectiveness of dietary management in IBS.
The aim of the study is to investigate and compare the effectiveness of a Mediterranean Modified Low FODMAP diet (Med-Mod LFD) with standard Mediterranean dietary recommendations (Med standard) in managing the symptoms of IBS. Specifically, the study aims to evaluate the impact of the two dietary interventions on the frequency and severity of gastrointestinal symptoms, to examine potential differences in quality of life, to assess patient compliance and acceptance of the two dietary approaches, and to explore whether the Med-Mod Low FODMAP variation of the Mediterranean diet offers advantages over the classical Mediterranean diet without compromising the health-promoting characteristics that make it beneficial.Dietary intake will also be assessed using a three-day food diary, which will be used for the dietary analysis of participants' food intake and for the assessment of macro- and micronutrient intake of the two dietary interventions
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Mediterranean Standard Diet | Active comparator | Other: Mediterranean Standard DietAll participants in this group will be instructed to follow Mediterranean diet recommendations, based on the Greek National Dietary Guidelines, for the management of Irritable Bowel Syndrome for a period of 6 weeks. |
| Mediterranean Modified Low FODMAP Diet | Experimental | Other: Mediterranean Modified Low FODMAP DietAll participants in this group will initially follow the Mediterranean Modified Low FODMAP Diet during Phase 1 (the elimination phase) for 6 weeks. During Phase 2 (the reintroduction phase), patients will gradually reintroduce foods high in FODMAPs over a period of 6-8 weeks and assess their individual tolerance. During Phase 3 (the maintenance phase), following the reintroduction of high-FODMAP foods, patients will follow an individualized diet based on their personal tolerance, combining high- and low-FODMAP foods. |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Diagnosis of IBS according to the Rome V criteria (IBS-C, IBS-D, IBS-U, IBS-M)
- Age 18-65 years
- Provision of written informed consent
- Caucasian ethnicity
Key exclusion criteria (6 listed)
- Any comorbid condition requiring a specialized or medically restricted diet, such as renal failure, diabetes mellitus, celiac disease, cerebrovascular disorders of the central nervous system, food allergies, or a history of major abdominal surgery
- Εating disorders
- Recent use of antibiotics or probiotics within 1 month before the intervention
- Current hypnotherapy
- Pregnancy
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Mediterranean Standard DietMediterranean diet recommendations for a period of 6 weeks | Other | Mediterranean Standard Diet |
| Mediterranean Modified Low FODMAP DietMediterranean-modified low-FODMAP dietary program, including elimination, reintroduction and personalization/maintenance phases | Other | Mediterranean Modified Low FODMAP Diet |
Primary outcome
Change in symptom severity from baseline to post-intervention, assessed using a validated disease-specific questionnaire.
Time frame: Baseline, 6 Weeks and 6 months
The Irritable Bowel Syndrome Severity Scoring System (IBS-SSS) consists of five items, each accompanied by specific scoring instructions. The five items assess pain severity, pain frequency, severity of abdominal distension, satisfaction with bowel habits, and the impact of IBS on quality of life. Each item is scored from 0 to 100 using a visual analogue scale (VAS), yielding a total score ranging from 0 to 500, with higher scores indicating greater symptom severity. Patients may be classified as having mild (75-175), moderate (175-300), or severe (>300) IBS. A reduction of 50 points is considered clinically meaningful.
4 secondary outcomes
Assessment of IBS-related quality of life using a disease-specific questionnaire before and after the intervention, with comparisons between the study groups.
Time frame: Baseline, 6 weeks and 6 months
Bristol Stool Form Scale (BSFS), Type 1-7
Time frame: baseline, 6 weeks and 6 months
Assessment of anxiety and depressive symptoms before and after the intervention.
Time frame: Baseline, 6 weeks and 6 months
Mediterranean Diet Adherence Score
Time frame: Baseline, 6 weeks and 6 months
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 28 Oct 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Questions about this trial
What is this clinical trial studying?
A study testing Mediterranean Standard Diet and Mediterranean Modified Low FODMAP Diet in people with Irritable Bowel Syndrome, run by University Hospital of Patras.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 28 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Christos Triantos, MD, Phd (+306972894651, chtriantos@hotmail.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in symptom severity from baseline to post-intervention, assessed using a validated disease-specific questionnaire. (time frame: Baseline, 6 Weeks and 6 months). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 28 Oct 2026.