The present invention discloses different specific bacterial strains isolated from individuals without caries which are characterized in that they present inhibitory activity against cariogenic organisms. The invention also discloses a process for isolating said strains, as well as bioactive peptides, such as anti-microbial peptides of human and bacterial origin, which also show anti-cariogenic activity. Moreover, the present invention also discloses pharmaceutical and/or probiotic/prebiotic compositions, functional foods, mouthwashes, toothpaste, chewing gum, etc., that comprise at least one of the strains and/or at least one of the bioactive peptides described in the invention, or a combination thereof, which are useful in the treatment and/or prevention of infectious diseases of the buccal cavity, preferably caries.
