1. Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Milan, Italy
2. Gastroenterology and Endoscopy Unit, Fondazione IRCCS Cà Granda, Ospedale Maggiore Policlinico, Milan, Italy
3. Division of Gastroenterology, Washington University School of Medicine, St. Louis, Missouri
4. Division of General and Bariatric Surgery, Department of Surgery, Second University of Naples, Naples, Italy
5. Division of Gastroenterology, Department of Surgery, Oncology and Gastroenterology, University of Padua, Padua, Italy
6. Division of Gastroenterology, Department of Translational Research and New Technology in Medicine and Surgery, University of Pisa, Cisanello Hospital, Pisa, Italy