Traditional Dietary Advice Vs. Mediterranean Diet in IBS

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

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.

Study Overview

• Status: Recruiting
• Conditions: Irritable Bowel Syndrome
• Intervention / Treatment: Other: Traditional Diet; Other: Mediterranean Diet

• Study Type: Interventional
• Enrollment (Estimated): 134
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Jemima Clarke; Phone Number: 01142265943; Email: sth.researchadministration@nhs.net

Study Locations

• United Kingdom
  • South Yorkshire
    • Sheffield, South Yorkshire, United Kingdom, S10 2JF
      • Recruiting
      • Royal Hallamshire Hospital
      • Contact: Jemima Clarke; Phone Number: 01142265943; Email: sth.researchadministration@nhs.net
      • Principal Investigator: Imran Aziz, MD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Traditional Dietary Advice; Its main elements are to adopt sensible eating habits and avoid excess fatty foods, spicy foods, processed foods, caffeine, fizzy drinks and alcohol.	Other: Traditional Diet; Provided as an educational leaflet
Active Comparator: Mediterranean Diet; The principle components is a diet rich in vegetables, pulses, whole grains, and olive oil	Other: Mediterranean Diet; Provided as an educational leaflet

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Proportion of IBS patients experiencing clinical response with traditional dietary advice vs. Mediterranean diet	IBS symptom severity scale (IBS-SSS) where a 50-point reduction denotes a meaningful clinical response	Baseline to Week 6

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Changes in individual items of the IBS-SSS	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.	Baseline to Week 6
Changes in Anxiety and Depression	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	Baseline to Week 6
Changes in Somatic Symptom reporting	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	Baseline to Week 6
Changes in quality of life	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	Baseline to Week 6
Dietary satisfaction to assigned intervention	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.	Week 6
Adherence to the Mediterranean diet	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.	Week 6
Changes in nutritional intake	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	Baseline to Week 6

Collaborators and Investigators

• Sponsor: Sheffield Teaching Hospitals NHS Foundation Trust
• Investigators: Principal Investigator: Imran Aziz, Sheffield Teaching Hospitals Nhs Foundation Trust

Study record dates

Study Major Dates

• Study Start (Actual): September 30, 2023
• Primary Completion (Estimated): May 31, 2026
• Study Completion (Estimated): May 31, 2026

Study Registration Dates

• First Submitted: July 25, 2023
• First Submitted That Met QC Criteria: August 2, 2023
• First Posted (Actual): August 9, 2023

Study Record Updates

• Last Update Posted (Actual): April 22, 2024
• Last Update Submitted That Met QC Criteria: April 18, 2024
• Last Verified: April 1, 2024

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Digestive System Diseases; Pathologic Processes; Disease; Gastrointestinal Diseases; Colonic Diseases, Functional; Colonic Diseases; Intestinal Diseases; Syndrome; Irritable Bowel Syndrome
• Other Study ID Numbers: STH20655b

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