1. Department of Pathomorphology, The Children’s Memorial Health Institute, Aleja Dzieci Polskich 20, 04-730 Warszawa, Poland
2. Department of Paediatric Endoscopy and Gastrointestinal Function Testing, Ludwik Rydygier Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Torun, Bydgoszcz, 87-100 Toruń, Poland
3. Department of Pediatrics, Faculty of Medical Sciences, Medical University of Silesia in Katowice, 40-055 Katowice, Poland
4. Department of Gastroenterology, Hepatology, Nutritional Disorders and Pediatrics, The Children’s Memorial Health Institute, Aleja Dzieci Polskich 20, 04-730 Warsaw, Poland
5. Department of Paediatric Rehabilitation, The Children’s Memorial Health Institute, Aleja Dzieci Polskich 20, 04-730 Warszawa, Poland
6. Laboratory of Anthropology, The Children’s Memorial Health Institute, Aleja Dzieci Polskich 20, 04-730 Warszawa, Poland
7. Hepatology and Nutrition Unit, Gastroenterology, Paediatric Department, University Medical Centre Maribor, 2000 Maribor, Slovenia
8. Paediatric Department, Faculty of Medicine, University of Maribor, 2000 Maribor, Slovenia