1. Murdoch Children's Research Institute, The Royal Children’s Hospital, and the University of Melbourne, Melbourne, Victoria, Australia;
2. Department of Mathematics, Duquesne University, Pittsburgh, Pennsylvania;
3. University of Pittsburgh Medical Center St. Margaret’s Hospital, Pittsburgh, Pennsylvania;
4. Department of Pediatrics, Epidemiology and Biostatistics, School of Medicine, University of California, San Francisco, San Francisco, California;
5. University of Toronto and The Hospital for Sick Children, Toronto, Ontario, Canada;
6. Ospendale Infantile Regina Margherita, Citta della Salute e della Scienza di Torino, Torino, Italy;
7. Department of Paediatrics, The Medical University of Warsaw, Warsaw, Poland;
8. Department of Neonatology, Nepean Hospital and Sydney Medical School Nepean, University of Sydney, Sydney, New South Wales, Australia;
9. Department of Pediatric Gastroenterology, Paris Descartes University and Necker-Enfants Malades Hospital, Paris, France;
10. Department of Pediatrics, University of Bari, Bari, Italy;
11. Bacteriology Unit, National Institute for Health and Welfare, Helsinki, Finland;
12. Department of Pediatrics and Adolescent Medicine, Turku University Hospital, Turku, Finland; and
13. Department of Pediatrics, University of California Davis Health System, Sacramento, California