1. Department of Hygiene, Epidemiology and Ergonomics; Medical University of Bialystok; Bialystok Poland
2. Department of Physiology; Medical University of Bialystok; Bialystok Poland
3. Department of Gastroenterology and Internal Medicine; Medical University of Bialystok; Bialystok Poland
4. Department of Conservative Dentistry; Medical University of Bialystok; Bialystok Poland