Understanding how environmental factors, diet and gut micro-organisms influence Crohn’s Disease and Ulcerative Colitis flare.


PREdiCCt is a major study in the UK.

The focus of the study is towards understanding how diet, lifestyle and the bacteria in your gut influence flare and recovery in Crohn’s disease and ulcerative colitis. To achieve this we recruited 2629 people with IBD (age 6 and upwards) across 49 hospitals in the UK. Our participants are followed up over 2 years whilst collecting information on the food they eat, their lifestyle and their gut bacteria. Accordingly, it may be possible to find a link between these factors and the severity of each participant’s symptom flares.

Studying Disease Flares in IBD

  • How often do disease flares occur in IBD?
  • What causes disease flare in IBD?
  • Can we predict who will flare?
  • What can people with IBD do to prevent flares?
  • Can we work out what factors are associated with prolonged (deep) remission?

What do we hope to achieve?

  1. Finding out the environmental and dietary factors for patients to avoid because they trigger flare.
  2. Finding out behaviours for patients to adopt because they bring about remission.
  3. Finding out what the microorganisms that predict flare look like.
  4. Gaining information which helps future studies aimed at finding better diets for IBD sufferers.
  5. Developing ways of gathering information online from IBD patients about their well-being that doctors can routinely use.

Study Data

The study has now finished recruiting and we are starting to look at the baseline data from our participants.  We are looking at lots of different data:


Baseline phenotyping including date of diagnosis, disease location and behaviour, current and prior drug therapy, surgical interventions, family history, and smoking status. Plus standard clinical care blood tests.

Environmental, Lifestyle and Dietary Data Collection

Food Frequency Questionnaire & 4-day weighed food diary. This gives us an idea of what people eat over a longer period of time as well as during the days when they join the study. We also ask participants to complete questionnaires on quality of life, emotions & mood, stressful life events, physical activity, sleep, drug adherence and foreign travel.

Saliva and Stool Samples

Stool samples are analysed for Faecal Calprotectin and Short chain fatty acids measured on stool samples. The saliva samples are analysed for DNA.


24 months follow-up of all participants. Questionnaires are emailed through the PREdiCCt web-portal every month. We ask our participants how they are, if they have been sick or anything significant has happened and if they have had a flare. While recruitment has finished, follow up data collection continues as before for our participants.

At flare participants return further stool samples for microbiome and faecal calprotectin analysis. Multiple flares are captured during the study.

The Study Team

The PREdiCCt study is coordinated by the University of Edinburgh and NHS Lothian and has contributions from gastroenterologists & research scientists across the UK. It is funded by Cure Crohn’s & Colitis, Crohn’s and Colitis in Childhood, NHS Lothian and the Chief Scientist Office.

You can follow the study and get in touch via: