1 Division of Digestive Diseases, Department of Metabolism, Digestion and Reproduction, St Mary's Hospital Campus, Imperial College London, London, UK.
2 Departments of Gastroenterology and Hepatology, St Mary's Hospital, Imperial College Healthcare NHS Trust, London, UK.
3 Section of Bioinformatics, Division of Systems Medicine, Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, London, UK.
4 Division of Gastroenterology, Hepatology, and Endoscopy, Brigham and Women's Hospital, Boston, Massachusetts, USA.
5 Harvard Medical School, Boston, Massachusetts, USA.