Prebiotic and probiotic treatment to reduce oral dysbiosis and promote eubiosis

Provided herein is a composition comprising nitrate for use in reducing or preventing oral dysbiosis and/or increasing oral eubiosis, by changing the bacterial composition and functions thereof of oral biofilms in a mammal, by decreasing the amount of disease-associated bacteria and increasing the amount of health-associated bacteria, thereby getting an acute treatment or prevention with effects before 24 hours of a biofilm-mediated oral disease (e.g. caries, periodontal diseases - gingivitis, periodontitis or peri-implantitis - and halitosis), and wherein the composition is orally administered to the mammal and thereby increases the concentration of nitrate in the saliva of the mouth. The composition can also comprise a bacterial strain belonging to Rothia, Neisseria or Kingella genera, for use in increasing the nitrate-reduction capacity of a mammal.