1 Department of Gastroenterology, St Mary's Hospital, London W2 1NY, UK. Electronic address: Jonathansegal1@nhs.net.
2 University of Birmingham Microbiome Treatment Centre and Institute of Applied Health Research, University of Birmingham, Birmingham, UK; Department of Gastroenterology, Queen Elizabeth Hospital Birmingham, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK.
3 Department of Gastroenterology, Royal Wolverhampton NHS trust, Wolverhampton, UK; University of Wolverhampton, Wolverhampton, UK.