1. Gastroenterology and Endoscopy, IRCCS Ospedale San Raffaele and Vita-Salute San Raffaele University , Milan , Italy
2. Department of Biomedical Sciences, Humanitas University , Pieve Emanuele, Milan , Italy
3. University of Lorraine, CHRU-Nancy, Department of Gastroenterology , F-54000 Nancy , France
4. University of Lorraine, Inserm, NGERE , F-54000 Nancy , France