An international research team led by the University of Melbourne will run a world-first head-to-head clinical trial, comparing the effectiveness of two opposite Irritable Bowel Syndrome (IBS) treatments, the low FODMAP* diet and exposure-based cognitive behavioural therapy.
The study aims to understand who benefits most from diet versus psychological therapy, so clinicians can match the right treatment to the right patient from the outset, saving patients time and money while also reducing their suffering.
The trial follows a recent six-month longitudinal study which found that while the low FODMAP diet — widely regarded as the gold standard for managing IBS — helps most patients, around 21 per cent show little to no benefit, highlighting the need for more tailored treatment strategies.
Up to 20 per cent of Australians suffer from IBS and for many, this chronic gastrointestinal disorder can be debilitating with common symptoms including abdominal pain, constipation, diarrhoea, bloating and unpredictable bowel movements.
Exposure-based Cognitive Behavioural Therapy (CBT) helps IBS patients gradually reintroduce symptom-inducing foods into their diets, reshaping the gut-brain response through structured psychological exercises.
Alternatively, the low FODMAP diet removes triggering foods from the patients' meal plans.
Lead researcher Associate Professor Jessica Biesiekierski said while both treatments are already used in clinical practice with similar success rates, until now no one has directly compared them or identified the factors which determine why patients respond better to one treatment over the other.
"Patients with IBS are often stuck in a frustrating and expensive trial-and-error cycle of appointments, tests, emergency visits, different treatments, medications, as well as invasive procedures trying to find what works," Associate Professor Biesiekierski said.
"Because there's no single solution, people can go years without real relief. Our study aims to help fast-track patients to the right treatment, saving time, money, and improving quality of life."
The research team is recruiting 200 people across Australia and the United States to take part in the free trial, which will be conducted remotely.
Participants are randomly assigned to receive either the low FODMAP diet or CBT and will undergo 12 weeks of treatment with regular one-on-one support from a dietitian or psychologist.
Participants will have follow-up appointments at the three-month and six-month marks to see whether their symptom benefits have remained.
The clinical trial is in collaboration with Monash University, Harvard Medical School, Massachusetts General Hospital and Karolinska Institute.
Expressions of Interest are now open, you can find out more information here: https://gutresearchstudy.com
*FODMAP stands for Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols.
