1 Department of Public Health and Preventive Medicine, Faculty of Medicine, and Helicobacter pylori and Microbiota Study Group, Institute of Tropical Disease, Universitas Airlangga, Surabaya 60115, Indonesia; Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Yufu, Japan. Electronic address: kartikafauzia@gmail.com.
2 Department of Endoscopy, Cho Ray Hospital, Ho Chi Minh, Vietnam.