1. Department of Gastroenterology, Hospital Universitario Central de Asturias, Oviedo, Spain
2. Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Principado de Asturias, Oviedo, Spain
3. NIHR Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust and University of Nottingham, Nottingham, United Kingdom