Skip to main content
OpenTrials
Completed

NCT Number: NCT05985018

Traditional Dietary Advice Vs. Mediterranean Diet in IBS

Irritable bowel syndrome (IBS) affects 5-10% of the population, and incurs substantial health impairment and healthcare utilization. Over 80% of individuals with IBS report food to trigger or aggravate symptoms, with many seeking to undertake dietary modifications. Current guidelines recommend first-line therapy with the relatively straightforward traditional dietary advice, with the more complex and restrictive low FODMAP diet reserved as second-line therapy.

There is emerging data suggesting that the Mediterranean diet may also improve the symptoms of IBS, although it has not yet been subject to any head-to-head randomized dietary trials to help position it within the treatment algorithm. Given the relative ease of implementing the Mediterranean diet, alongside its recognized cardio-metabolic and mental health benefits, studying its efficacy in IBS is attractive as it could potentially pave the way for another first-line dietary option being available to patients before escalating to the demanding and resource intensive second-line therapies.

The investigators will perform a randomized trial comparing the clinical efficacy of traditional dietary advice vs. a Mediterranean diet in IBS. Following dietary randomization, participants will complete validated questionnaires to assess changes in IBS symptoms, quality of life, mood, somatic symptoms, nutritional status, as well as dietary satisfaction and adherence.

Completed

Looking for future studies?

Notify Me

Key information

Conditions

Irritable Bowel Syndrome Colonic Diseases Colonic Diseases, Functional Digestive System Diseases Gastrointestinal Diseases Intestinal Diseases

Age range

18 year–65 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Royal Hallamshire Hospital

Sheffield, South Yorkshire, S10 2JF, United Kingdom

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • IBS Symptom Severity Scale(IBS-SSS) > 75
  • Online access
  • English literate

Exclusion criteria

  • Organic gastrointestinal diseases (e.g. inflammatory bowel disease, GI cancer, coeliac disease, microscopic colitis, bile acid diarrhoea)
  • Major abdominal surgery (except laparoscopy, appendectomy, cholecystectomy)
  • History of eating disorder
  • Body mass index <20
  • Current dietary interventions
  • Current use of opioids/antibiotics
  • Titrating dose of neuromodulators
  • Severe systemic disease (e.g. cardiac, renal, respiratory, psychiatric) necessitating frequent medical consultations/hospitilisations
  • Pregnant
  • Diabetes mellitus
  • Scleroderma
  • Memory impairment

Treatment and study plan

Traditional diet

Other

Provided as an educational leaflet

Mediterranean Diet

Other

Provided as an educational leaflet

Primary outcomes

  1. Proportion of IBS patients experiencing clinical response with traditional dietary advice vs. Mediterranean diet

    Time frame: Baseline to Week 6

    IBS symptom severity scale (IBS-SSS) where a 50-point reduction denotes a meaningful clinical response

Secondary outcomes

  1. Changes in individual items of the IBS-SSS

    Time frame: Baseline to Week 6

    IBS- SSS contains 5 specific questions (pain severity, pain frequency, abdominal distension severity, bowel movement satisfaction, quality of life) with score ranging from 0-100. Change in individual items will be compared within- and between- groups.

  2. Changes in Anxiety and Depression

    Time frame: Baseline to Week 6

    The four-item patient health questionnaire (PHQ-4) for anxiety and depression is a validated questionnaire assessing mood, with higher scores representing worse mood. Change in scores will be compared within- and between- groups

  3. Changes in Somatic Symptom reporting

    Time frame: Baseline to Week 6

    The validated patient health questionnaire-12 assess extra-intestinal somatic symptoms, with higher scores representing greater somatic symptom severity. Change in scores will be compared within- and between- groups

  4. Changes in quality of life

    Time frame: Baseline to Week 6

    The validated Short form 8 Quality of life Questionnaire assesses quality of life, with higher scores representing better quality of life. Change in scores will be compared within- and between- groups

  5. Dietary satisfaction to assigned intervention

    Time frame: Week 6

    The Diet Satisfaction Score is a 10-item questionnaire assessing dietary satisfaction to an allocated diet (either Mediterranean diet or traditional diet), with higher scores representing greater satisfaction. Changes in score will be compared between the groups.

  6. Adherence to the Mediterranean diet

    Time frame: Week 6

    The 14-point Mediterranean Diet Adherence Screener will check adequate dietary adherence, which we expect will be seen in those assigned a Mediterranean diet compared with traditional diet. Higher scores represent better adherence.

  7. Changes in nutritional intake

    Time frame: Baseline to Week 6

    The Comprehensive Nutritional Assessment Questionnaire assesses macronutrient and micronutrient intake, FODMAPs, fibre, starch, glycaemic index/load. Change in scores will be compared within- and between- groups. Only a subset will complete this

Sponsors and collaborators

Lead sponsor

Sheffield Teaching Hospitals NHS Foundation Trust

Other

Registry information

Official study title

A Randomized Trial of Traditional Dietary Advice Versus Mediterranean Diet in Irritable Bowel Syndrome

Important dates

Study start
2023
Primary completion
2024
Study completion
2024
First posted
Aug 9, 2023
Registry last updated
Mar 14, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Related clinical trials

Published trials that share one or more normalized conditions with this study.