1 Gastroenterology Unit, Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa (Nicola de Bortoli, Lucia Mariani), Italy.
2 Pediatrics Unit, Department of Experimental and Clinical Medicine, University of Pisa (Teresa Di Chio), Italy.
3 Gastroenterology Unit, Department Surgery, Oncology and Gastroenterology, University of Padua (Edoardo V. Savarino), Italy.