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Traditional Dietary Advice Vs. Mediterranean Diet in IBS

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

Status
Completed
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT05985018
Enrollment
139
Registered
2023-08-09
Start date
2023-09-30
Completion date
2024-12-20
Last updated
2025-03-14

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Irritable Bowel Syndrome

Brief summary

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.

Interventions

Provided as an educational leaflet

OTHERMediterranean Diet

Provided as an educational leaflet

Sponsors

Sheffield Teaching Hospitals NHS Foundation Trust
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE

Eligibility

Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
No

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

Design outcomes

Primary

MeasureTime frameDescription
Proportion of IBS patients experiencing clinical response with traditional dietary advice vs. Mediterranean dietBaseline to Week 6IBS symptom severity scale (IBS-SSS) where a 50-point reduction denotes a meaningful clinical response

Secondary

MeasureTime frameDescription
Changes in Anxiety and DepressionBaseline to Week 6The 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
Changes in Somatic Symptom reportingBaseline to Week 6The 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
Changes in quality of lifeBaseline to Week 6The 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
Changes in individual items of the IBS-SSSBaseline to Week 6IBS- 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.
Adherence to the Mediterranean dietWeek 6The 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.
Changes in nutritional intakeBaseline to Week 6The 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
Dietary satisfaction to assigned interventionWeek 6The 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.

Countries

United Kingdom

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026