Clinical trial NCT06912828: GWAS to Identify Predictive Genetic Factors for the Success of Dietary Intervention in the Treatment of IBS Symptoms
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
Study type: OBSERVATIONAL
Overall status: RECRUITING
Conditions: Irritable Bowel Syndrome (IBS)
Genome-wide Association Study
Single Nucleotide Polymorphisms
Mediterranean Diet
FODMAP Diet
Keywords: diet response
nutrigenetics
Lead sponsor: Attikon Hospital
Sponsor class: OTHER
First posted: 2025-04-06
Enrollment: 100
Sex: ALL
Minimum age (years): 18
Maximum age (years): 65
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: CASE_ONLY
Time perspective: PROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
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.

Brief 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 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.

Eligibility criteria: Inclusion Criteria:

* Fulfillment of the Rome IV criteria for IBS
* Provision of written informed consent.
* Commitment of availability throughout the study period.
* IBS-SSS \> 175

Exclusion Criteria:

* 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.

Primary outcomes:
measure: Find single nucleotide polymorphisms (SNPs) that associate with the diet respone
timeFrame: Baseline
Secondary outcomes:
measure: Change of symptoms severity pre and post intervention using a specialized questionnaire.
timeFrame: Baseline and through study completion (an average of 1 year)
measure: Evaluation of the effect of interventions on gut microbiota composition between groups.
timeFrame: Baseline and through study completion (an average of 1 year)
measure: Assessment of general quality of life pre and post intervention between groups
timeFrame: Baseline and through study completion (an average of 1 year)
measure: Assessment of symptoms burden in general pre and post intervention.
timeFrame: Baseline and through study completion (an average of 1 year)
measure: Assessment of anxiety and depression disorders pre and post intervention.
timeFrame: Baseline and through study completion (an average of 1 year)
Other outcomes:
Locations:
city: Athens
country: Greece
facility: Attikon General University Hospital of Athens
Study officials:
References: