1 Department of Internal Diseases, Gastroenterology and Dietetics, North-Western State Medical University named after I.I. Mechnikov, St. Petersburg, Russia.
2 Department of Microbiology, State Research Institute of Highly Pure Biopreparations, St. Petersburg, Russia.
3 Institute of Perinatology and Pediatrics, Almazov National Medical Research Centre, St. Petersburg, Russia.
4 Department of Internal Diseases, Rīga Stradiņš University, Riga, Latvia.
5 Centre of Gastroenterology, Hepatology and Nutrition, Pauls Stradiņš Clinical University Hospital, Riga, Latvia.