1. Health Centre 4, LV-1012 Riga, Latvia
2. Digestive Diseases Center GASTRO, LV-1079 Riga, Latvia
3. Department of Doctoral Studies, Riga Stradins University, LV-1007 Riga, Latvia
4. Department of Internal Diseases, Riga Stradins University, LV-1007 Riga, Latvia
5. Institute of Clinical and Preventive Medicine, University of Latvia, LV-1586 Riga, Latvia
6. Riga East University Hospital, LV-1038 Riga, Latvia