Lactic acid bacteria (LAB) are a group of micro-organisms that have the capacity of produce several substances with antagonist activity. Studies have shown that many LAB have the capacity to assist in the treatment of certain pathologies, even as to prevent the caries. The development of caries occurs due to the formation of a cavity in the tooth surface caused by destruction of enamel protein by bacteria, especially Streptococcus mutans, as one of the micro-organisms related to this problem. Once show LAB is capable of inhibiting the cariogenic bacteria, it is interesting through food conveying aimed at preventing disease. The aim of this study was to determine in vitro antagonistic activity of Lactobacillus brevis ATCC 367 against Streptococcus mutans ATCC 700610 and studying the viability of the bacteria applied in chewing gums. Using the spot-on-the-lawn method was evaluated the antagonistic activity against S. mutans and the identity of the antagonism. L. brevis was microencapsulated by spray drying technique, applied in chewing gums ( 9.36 log CFU. g-1) and examined during the storage period (1, 9, 17, 25 and 33 days). L. brevis demonstrated significant inhibitory capacity of cariogenic bacteria when compared to oral antiseptic (chlorhexidine 0.2%), which was due a peptide, and remained viable reaching at 33 days a concentration greater than 8 log CFU. g-1. L. brevis showed ability to inhibit in vitro S. mutans, considered potentially effective against cariogenic bacteria and its viability in chewing gums justifies future studies to verify efficacy a functional food in preventing caries.