1. Gastroenterology of Pediatric Unit, Maggiore Hospital, Bologna, Italy;
2. Department of Biological, Geological and Environmental Sciences, University of Bologna, Bologna, Italy;
3. Anatomy, Histology and Cytodiagnostic Unit, Maggiore Hospital, Bologna, Italy;
4. Graduate School of Pediatrics, University of Ferrara, Ferrara, Italy;
5. Department of Agricultural Sciences, University of Bologna, Bologna, Italy