https://www.gazetawarszawska.com/index.php/scientia-et-arte/7243-kefir-chroni-przed-wirusem-cov19-3?fbclid=IwAR0U44Knpwhn5iPqcOGmEtzlWDOaBMn0W9wgoINlZg8OokVH1FlU26WtuCA