[1] Univ Pisa, Dept Translat Res & New Technol Med & Surg, I-56126 Pisa, Italy
[2] Hosp Angeles Pedregal, Gastroenterol & Neuroenterol & Motil, Mexico City 10700, DF, Mexico
[3] Hosp Gen Agudos Dr Ignacio Pirovano, Paediat Gastroenterol & Nutr Sect, C1428, Buenos Aires, DF, Argentina
[4] Hosp Gen Univ Gregorio Maranon, Sect Pediat Gastroenterol & Nutr, Madrid 28007, Spain
[5] Sanofi, D-65929 Frankfurt, Germany
[6] Univ Sao Paulo HC FMUSP, Hosp Clin, Inst Crianca & Adolescente, Allergy & Immunol Div,Pediat Dept,Fac Med, BR-05403000 Sao Paulo, Brazil