1. Division of Gastroenterology; University of Pisa; Pisa Italy
2. Division of Gastroenterology; University of Padua; Padua Italy
3. Obesity Research Center; Endocrinology Unit; University of Pisa; Pisa Italy
4. Department of Clinical and Experimental Medicine; University of Pisa; Pisa Italy
5. Division of Gastroenterology; University of Genoa; Genoa Italy
6. Digestive Pathophysiology Unit; New S. Agostino Hospital; Modena Italy