What is the health problem?

Crohn's disease and ulcerative colitis are the most common types of inflammatory bowel disease (IBD), a group of long-term autoimmune diseases, which cause inflammation, in the digestive system. Treatment for IBD depends on how severe symptoms are. In the first instance, patients will take conventional chemically synthesised medicines. If these do not work – and the IBD is severe – patients will be recommended a new biologic drug that stops inflammation. Unlike chemical medications, this type of medicine is made out of materials also found in living organisms.

However, patients respond differently to this biologic drug. Some benefit, whereas others do not, or even have unwanted side effects. Those who do not respond are treated with a different biologic drug or may require surgery because inflammation has worsened. This trial-and-error approach is unsatisfactory.

There is a pressing need to better match individual patients with safe and effective biologic drugs that work for them. The gut microbiome – the large and complex community of typically harmless bacteria in our intestines – has an important influence over biologic drug response. Yet, no products exist which probe the microbiome to forecast biologic drug response in IBD.  

What is the aim of this study?

In this study, a precision medicine company, AlphaBiomics, will develop a test (called RxSelex) that predicts whether individual patients with IBD are likely to respond positively to biologic drugs. 

This will be done by measuring important stool microbiome components, ensuring the appropriate drug is prescribed. The benefits achieved using this test could be substantial, including increased patient quality of life, together with improved cost benefits to the NHS, society, and the economy. 

The researchers will assess that RxSelex correctly predicts treatment response of patients in the UK and the Netherlands, to develop laboratory tests and computer programmes needed for RxSelex, and also to analyse its impact on patients experiencing IBD and on the NHS. 

The involvement of patients with IBD is crucial to this study, and will be supported by experts in the ARC’s patient and public involvement research theme. Patients will be involved throughout the study advising and guiding researchers drawing on their unique insights and experiences. 

The ultimate aim is to generate the evidence required to bring RxSelex to market and to speed adoption by the NHS and healthcare systems globally.

This research is funded by the NIHR Invention for Innovation (i4i) Programme, which supports the development of medical technologies in areas of existing or emerging patient need. 

How will the study be carried out?

The study will be conducted over four stages:

  1. Recruit 300 IBD patients from leading gastroenterology centres in the UK and the Netherlands and collect patient stool samples and metadata needed to validate the RxSelex prediction model
  2. Develop and validate the RxSelex assay laboratory protocols and the RxSelex software
  3. Integrate the perspective and insights from patients via a patient advisory group
  4. Develop the commercial, intellectual property (IP) and regulatory strategies.

How is the ARC involved?

Individuals with IBD are actively involved in this programme to inform research, design, and implementation of RxSelex and to support dissemination of involvement opportunities and results. 

The project team includes a patient representative with responsibility for project PPIE coordination and liaising between scientists and patients. Her efforts are supported by AlphaBiomics' PPIE Coordinator. All PPIE activities are supported by Sally Brearley (co-applicant) and Professor Mary Chambers, the ARC’s PPI research lead, and Laura Chapman (University of Birmingham), all experienced PPIE facilitators. 

Patients with IBD have already advised on the design of the study, patient recruitment, reviewed a stool collection kit, drafted patient-friendly instructions for use, and co-designed a UK-wide online survey. They will also co-author research updates, and help communicate research findings.


This project is a collaboration between industry, health service providers, and universities in the UK and the Netherlands. The collaborators include:

  • AlphaBiomics Ltd, UK
  • University of Birmingham, UK
  • University of Oxford, UK
  • London North West Healthcare NHS Trust (St Mark's Hospital)
  • Academic Medical Center Amsterdam, Netherlands
  • Newcastle University, UK
  • Patient Representative, UK
  • NIHR ARC South London and the Centre for Public Engagement at Kingston University and St George's, University of London

This project was adopted by the ARC in March 2022 and is expected to finish in early 2023.