1 Department of Paediatrics, the Medical University of Warsaw, Warsaw, Poland. Electronic address: hania@ipgate.pl.
2 Institute of Gastroenterology, Nutrition and Liver Diseases, Schneider Children's Medical Center of Israel, Petach Tikvah, Israel; Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
3 Division of Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, Lille University Children's Hospital and Faculty of Medicine, Lille, France.
4 Department of Pediatrics, Emma Children's Hospital-AMC and VU University Medical Center, Amsterdam, The Netherlands.
5 Städtische Kliniken München Klinik für Kinder- und Jugendmedizin Klinikum Harlaching, Munich, Germany.
6 Childhood Nutrition Research Centre, UCL Institute of Child Health, London, United Kingdom.