The present invention relates to a microorganism belonging to the group of lactic acid bacteria characterized in that it is capable of specifically binding to Streptococcus mutans, wherein the specific binding is (i) resistant to heat treatment and/or (ii) resistant to protease treatment and/or (iii) calcium-dependent and/or (iv) formed within a pH range between 4.5 and 8.5 and/or (v) formed in the presence of saliva. Preferably, the specific binding can be assayed as follows: (a) growing said microorganism to stationary phase (b) mixing said microorganism with Streptococcus mutans which has been grown to stationary phase (c) incubating the mixture obtained in step (b) under conditions allowing the formation of aggregates of said microorganism and Streptococcus mutans and (d) detecting aggregates by the occurrence of a pellet. Another aspect of the present invention is an analog or fragment of said microorganism which is thermally inactivated or lyophilized, wherein said analog or fragment retains the capability of specifically binding to Streptococcus mutans. In addition, the present invention encompasses compositions and additives for food, feed or drinks comprising the microorganism belonging to the group of lactic acid bacteria which specifically bind to Streptococcus mutans or an analog or fragment thereof. Moreover, uses of said microorganism or said analog or fragment thereof for the preparation of an anticariogenic or pharmaceutical composition or anticariogenic food or feedstuff as well as methods for producing said compositions or food or feedstuff are provided by the present invention.
