*Department of Translational Medical Sciences, Section of Pediatrics, University of Naples Federico II, Naples, Italy†Departamento de Pediatria Médica, Hospital de São João, Porto, Portugal‡KEMRI/Wellcome Trust Research Programme, Kilifi, Kenya§Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia||Department of Pediatrics, University of Alabama at Birmingham, Birmingham¶INTA, Universidad de Chile, Macul, Chile#Department of Pediatrics, Universidad Peruana Cayetano Heredia, Lima, Peru**Department of Paediatric Gastroenterology, Bristol Royal Hospital for Children, Bristol, United Kingdom††Department of Paediatrics, Hospital for Sick Children, University of Toronto, Toronto, Canada‡‡Department of Pediatrics and Adolescent Medicine, Juntendo University Graduate School of Medicine, Tokyo, Japan.