Irritable Bowel Syndrome (IBS)NCT06912828
GWAS to Identify Predictive Genetic Factors for the Success of Dietary Intervention in the Treatment of IBS Symptoms
An observational study of Irritable Bowel Syndrome (IBS) and Genome-wide Association Study, run by Attikon Hospital at 1 site in Greece.
Trial summary
This is a GWAS that aims to identify possible single nucleotide polymorphisms (SNPs) that are associated with the response in a combined dietary pattern low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols and Meditteranean diet (MED-LFD) in a small group of patients with Irritable Bowel… Read more about this study
- Who is it for?
- Ages 18 to 65 years
- Conditions the study is for
- Irritable Bowel Syndrome (IBS), Genome-wide Association Study, Single Nucleotide Polymorphisms
- What is being tested?
- Med-LFD intervention
- How many people
- 100 participants
- Where
- 1 siteGreece
- Study dates
- 15 Sep 2024to 15 Feb 2027
- Phase
- Observational
- 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
Study population: Patients 18-65 years with IBS (fullfiling ROME IV criteria) who have IBS-SSS>175. People with any concomitant disease requiring specialized nutrition, pregnant or lactating women will be excluded.
Who may be able to join
- Fulfillment of the Rome IV criteria for IBS
- Provision of written informed consent.
- Commitment of availability throughout the study period.
- IBS-SSS > 175
Who cannot join
- Any concomitant disease requiring specialized nutrition (e.g. renal failure, diabetes, celiac disease, cerebrovascular disease of the central nervous system, major surgical cavity).
- Pregnancy.
- Breastfeeding.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Greece1 site, 1 recruiting
- Recruiting
Attikon General University Hospital of Athens
Athens, 12462
About this study
Official title: Whole Genome Association Study (GWAS) to Identify Predictive Genetic Factors for the Success of Dietary Intervention in the Treatment of Irritable Bowel Syndrome (IBS) Symptoms
This is a GWAS that aims to identify possible single nucleotide polymorphisms (SNPs) that are associated with the response in a combined dietary pattern low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols and Meditteranean diet (MED-LFD) in a small group of patients with Irritable Bowel Syndrome (IBS).
Read the detailed description
Irritable bowel syndrome (IBS) is a very common chronic gastrointestinal disorder. Several factors seem to contribute to its development, such as psychological stress, intestinal dysbiosis, infections, post-traumatic syndrome and genetic predisposition. Regarding the nutritional management of IBS, there are several approaches to alleviate symptoms, such as the low-fructose diet low in fermentable oligosaccharides, disaccharides, monosaccharides and FODMAP polyols (LFD), recommendations from the British Institute of Health and Care Excellence (NICE) and the recently proposed combination of the Mediterranean diet and LFD (MED-LFD) proposed by our Research Group. However, genetic background expressed in single nucleotide polymorphisms (SNPs) appears to influence the response to even dietary interventions.
The aim of this GWAS is to identify SNPs that are associated with the negative or positive response to the diet.
At the baseline, blood samples will be collected for DNA extraction. Genotyping will be based on Next Generation Sequencing (NGS) technology to detect genetic factors associated with the effectiveness of the intervention. Symptom severity will be measured by the IBS-SSS scale. Mental health status will be assessed with the HADS (Hospital Anxiety and Depression Scale) questionnaire.
Patients will be recruited by the Department of Clinical Nutrition, Attikon University General Hospital, where the nutritional intervention will be carried out.
- Conditions
- Irritable Bowel Syndrome (IBS), Genome-wide Association Study, Single Nucleotide Polymorphisms, Mediterranean Diet, FODMAP Diet
- Being tested
- Med-LFD intervention
- Keywords
- diet response, nutrigenetics
- 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.
Med-LFD interventionOther
In the beginning of the intervention, blood and stool samples will be collected. All participants of the group at phase 1 (elimination phase), will initially follow the Med- LFD (2-6 weeks). At phase 2 (reintroduction phase), patients will gradually reintroduce foods rich in FODMAPs (6-8 weeks) and test their tolerance. At phase 3 (maintenance phase), following the reintroduction of foods rich in FODMAPs, patients will follow an individualized diet based on their personal tolerance (a combination of high and low FODMAPs). In the end of intervention, stool samples will be collected again.
| Study group | Role | What they receive |
|---|---|---|
| Basic group | MED-LFD Diet for 2 - 6 weeks. After this period there will be a reintroduction phase protocol that will last 6 - 8 weeks. Receives: Other: Med-LFD intervention |
What is being measured
The primary outcome is the main question the study is designed to answer.
Find single nucleotide polymorphisms (SNPs) that associate with the diet respone
Blood samples will be collected for DNA extraction. Genotyping be based on Next Generation Sequencing (NGS). Quality control (QC) filtering will be applied at individual-and variant-level using specialized software.
Measured: Baseline
Secondary outcomes (5)
Change of symptoms severity pre and post intervention using a specialized questionnaire.
IBS- SSS contains 5 specific questions with instructions on how to score them. Each of the five questions (pain severity, pain frequency, abdominal distension severity, bowel movement satisfaction, quality of life) ranges from 0 to a maximum score of 100 using a visual analog scale (VAS) with total scores ranging 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. A decrease of 50 points is associated with a clinically meaningful improvement.
Measured: Baseline and through study completion (an average of 1 year)
Evaluation of the effect of interventions on gut microbiota composition between groups.
Fecal samples will be collected from each participant and stored at -80°C.
Measured: Baseline and through study completion (an average of 1 year)
Assessment of general quality of life pre and post intervention between groups
12-Item Short Form Survey (SF-12) is a 12-item questionnaire used to assess generic health outcomes from the patient's perspective, covering the eight domains of health outcomes: physical functioning, role-physical, bodily pain, general health, vitality, social functioning, role-emotional \& mental health. The items are weighted and summed to provide physical and mental health scores (PCS and MCS). The two composite scores are computed using the scores on the questions that range from 0 to 100, with higher score indicating better health.
Measured: Baseline and through study completion (an average of 1 year)
Assessment of symptoms burden in general pre and post intervention.
The GSRS questionnaire was originally developed for dyspeptic patients but was later validated in patients with IBS. The GSRS is a 15-item questionnaire designed to assess common gastrointestinal symptoms. The questionnaire has five subscales, reflux, diarrhea, constipation, indigestion, and abdominal pain, with subscale scores ranging from 1 (no discomfort) to 7 (severe discomfort). Higher scores represent higher symptom burden.
Measured: Baseline and through study completion (an average of 1 year)
Assessment of anxiety and depression disorders pre and post intervention.
The Hospital Anxiety and Depression Scale (HADS) questionnaire is used for the assessment of anxiety and depression symptoms. It's a 14-item scale with seven items for each subscale, anxiety (HADS-A) and depression (HADS-D). Each item is scored on a response scale with four alternatives, ranging between 0 and 3. The total score is the sum of the 14 items, and for each subscale the score is the sum of the respective seven items (ranging from 0-21). A final score of 0-7 on each scale indicates that the patient has no symptoms, a score of 8-10 indicates mild symptoms while a score ≥11 indicates severe symptoms of anxiety and depressive disorders.
Measured: Baseline and through study completion (an average of 1 year)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted6 Apr 2025
- Study start15 Sep 2024
- Primary completion15 Sep 2026 (estimated)
- Study completion15 Feb 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Irritable Bowel Syndrome (IBS)Studies 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
- Observational
- Observational model
- Case only
- Time perspective
- Prospective
- Enrolment
- 100 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Attikon Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Arezina Kasti, Attikon Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06912828
- Sponsor's protocol ID
- ΕΒΔ407/30.5.2024
- Status last verified
- Mar 2025
- First submitted
- 14 Jan 2025
- Last updated
- 6 Apr 2025
- 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 6 Apr 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Whole Genome Association Study (GWAS) to Identify Predictive Genetic Factors for the Success of Dietary Intervention in the Treatment of Irritable Bowel Syndrome (IBS) Symptoms
- ClinicalTrials.gov ID
- NCT06912828
- Acronym / sponsor ID
- ΕΒΔ407/30.5.2024
- Conditions
- Irritable Bowel Syndrome (IBS), Genome-wide Association Study, Single Nucleotide Polymorphisms, Mediterranean Diet, FODMAP Diet
- Keywords
- diet response, nutrigenetics
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 100 participants (estimated)
- Lead sponsor
- Attikon HospitalUniversity, hospital or other
- Study start
- 15 Sep 2024 (actual)
- Primary completion
- 15 Sep 2026 (estimated)
- Study completion
- 15 Feb 2027 (estimated)
- First posted
- 6 Apr 2025 (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.
This is a GWAS that aims to identify possible single nucleotide polymorphisms (SNPs) that are associated with the response in a combined dietary pattern low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols and Meditteranean diet (MED-LFD) in a small group of patients with Irritable Bowel Syndrome (IBS).
Detailed description
Irritable bowel syndrome (IBS) is a very common chronic gastrointestinal disorder. Several factors seem to contribute to its development, such as psychological stress, intestinal dysbiosis, infections, post-traumatic syndrome and genetic predisposition. Regarding the nutritional management of IBS, there are several approaches to alleviate symptoms, such as the low-fructose diet low in fermentable oligosaccharides, disaccharides, monosaccharides and FODMAP polyols (LFD), recommendations from the British Institute of Health and Care Excellence (NICE) and the recently proposed combination of the Mediterranean diet and LFD (MED-LFD) proposed by our Research Group. However, genetic background expressed in single nucleotide polymorphisms (SNPs) appears to influence the response to even dietary interventions.
The aim of this GWAS is to identify SNPs that are associated with the negative or positive response to the diet.
At the baseline, blood samples will be collected for DNA extraction. Genotyping will be based on Next Generation Sequencing (NGS) technology to detect genetic factors associated with the effectiveness of the intervention. Symptom severity will be measured by the IBS-SSS scale. Mental health status will be assessed with the HADS (Hospital Anxiety and Depression Scale) questionnaire.
Patients will be recruited by the Department of Clinical Nutrition, Attikon University General Hospital, where the nutritional intervention will be carried out.
Study design
- Observational model
- Case only
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Basic group | – | Other: Med-LFD interventionMED-LFD Diet for 2 - 6 weeks. After this period there will be a reintroduction phase protocol that will last 6 - 8 weeks. |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Patients 18-65 years with IBS (fullfiling ROME IV criteria) who have IBS-SSS>175. People with any concomitant disease requiring specialized nutrition, pregnant or lactating women will be excluded.
Key inclusion criteria (4 listed)
- Fulfillment of the Rome IV criteria for IBS
- Provision of written informed consent.
- Commitment of availability throughout the study period.
- IBS-SSS > 175
Key exclusion criteria (3 listed)
- Any concomitant disease requiring specialized nutrition (e.g. renal failure, diabetes, celiac disease, cerebrovascular disease of the central nervous system, major surgical cavity).
- Pregnancy.
- Breastfeeding.
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 |
|---|---|---|
| Med-LFD interventionIn the beginning of the intervention, blood and stool samples will be collected. All participants of the group at phase 1 (elimination phase), will initially follow the Med- LFD (2-6 weeks). At phase 2 (reintroduction phase), patients will gradually reintroduce foods rich in FODMAPs (6-8 weeks) and test their tolerance. At phase 3 (maintenance phase), following the reintroduction of foods rich in FODMAPs, patients will follow an individualized diet based on their personal tolerance (a combination of high and low FODMAPs). In the end of intervention, stool samples will be collected again. | Other | Basic group |
Primary outcome
Find single nucleotide polymorphisms (SNPs) that associate with the diet respone
Time frame: Baseline
Blood samples will be collected for DNA extraction. Genotyping be based on Next Generation Sequencing (NGS). Quality control (QC) filtering will be applied at individual-and variant-level using specialized software.
5 secondary outcomes
Change of symptoms severity pre and post intervention using a specialized questionnaire.
Time frame: Baseline and through study completion (an average of 1 year)
Evaluation of the effect of interventions on gut microbiota composition between groups.
Time frame: Baseline and through study completion (an average of 1 year)
Assessment of general quality of life pre and post intervention between groups
Time frame: Baseline and through study completion (an average of 1 year)
Assessment of symptoms burden in general pre and post intervention.
Time frame: Baseline and through study completion (an average of 1 year)
Assessment of anxiety and depression disorders pre and post intervention.
Time frame: Baseline and through study completion (an average of 1 year)
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 6 Apr 2025.
- 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.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Irritable Bowel Syndrome (IBS) and Genome-wide Association Study, run by Attikon Hospital at 1 site in Greece.
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 3 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: looking for participants now, as of the sponsor's last update on 6 Apr 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Greece. Whether a site is taking part right now should be confirmed with that site. See every site.
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 Konstantinos Triantafyllou, Proffesor (+306977402690, ktriant@med.uoa.gr), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Find single nucleotide polymorphisms (SNPs) that associate with the diet respone (time frame: Baseline). 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 6 Apr 2025.