Irritable bowel syndrome (IBS) affects 1-in-10 people, with most patients identifying food as a key symptom trigger. While dietary intervention is central to IBS management, existing approaches — including the low FODMAP diet (LFD) and gluten-free diet (GFD) — carry significant drawbacks: complexity, cost, social restrictions, nutritional risk, and gut dysbiosis.
A series of randomised controlled trials systematically evaluated multiple dietary therapies. Head-to-head comparisons of traditional dietary advice (TDA), LFD, and GFD found all three to be effective, but TDA emerged as the most patient-friendly, and it is recommended as the first-line option. A recent UK trial demonstrated that the Mediterranean diet is also effective in IBS, positioning it as an additional first-line alternative before escalating to more restrictive therapies. Mechanistic analyses reveal important insights into nutritional and gut microbiome changes underpinning these effects.
Key Learning Points
· TDA should be considered the first-choice dietary therapy in IBS, with LFD and GFD reserved as second-line options
· The Mediterranean diet is effective in IBS and offers practical advantages, warranting inclusion in future clinical guidelines
· Dietary interventions in IBS produce measurable changes in nutritional status and gut microbiota, offering mechanistic understanding of therapeutic effects
Instructor
Dr Imran Aziz is a Consultant Gastroenterologist and Senior Lecturer at the University of Sheffield. He has successfully supervised 10 undergraduate BMedSci and postgraduate MD/PhD research students to thesis completion, with original articles published in high-impact journals. Numerous students have nominated him for the University of Sheffield Educational Awards. Drawing on his international expertise, Dr Aziz is a co-author of the British Society of Gastroenterology guidelines on the management of irritable bowel syndrome and functional dyspepsia.
In 2021, he was awarded the United European Gastroenterology Rising Star Award, recognising promising young clinician-scientists across Europe. He serves on the editorial board of Gastroenterology, a leading international journal in the field of gastrointestinal diseases, and chairs the Rome Partners Group, whose mission is to foster an international partnership between the Rome Foundation and early- and mid-career Neurogastroenterologists. In 2025, he was elected as a Rome Foundation Academic Fellow in recognition of his international standing as a clinical academic. In 2026, the Nutrition Society awarded him the Cuthbertson Medal for excellence in clinical nutrition research.
