Because of their association with a reduction in chronic inflammation and the displacement of pathogenic bacteria through bacterial adhesion, as well as concerns regarding antibiotic and antimicrobial resistance, dental researchers have begun to look at probiotics as a means to decrease oral disease. Very few randomized control trials have been conducted in this area, but preliminary research with some strains of bacteria show promise.

Researchers agree that in order for a microorganism to be considered an “oral probiotic,” it must adhere to and colonize surfaces in the oral cavity. To date, there is no agreement among researchers on the best probiotic for oral health. There have been several positive studies related to certain strains of Lactobacillus (e.g. Lactobaciluus rhamnosus GG, L. casei, L. reuteri) and dental caries, specifically the reduction of Streptococcus mutans. No long-term reduction in S. mutans has been shown, so prolonged administration of the probiotic would be necessary to achieve the effect. A reduction in gingivitis and bleeding has been shown with the administration of L. reuteri and the use of a periodontal dressing containing L. casei and collagen reduced some periodontal pathogens for up to one year following treatment. Culprits in oral malodor, the production of volatile sulfur compounds (VSC), have been shown to be reduced after ingestion of Weissella cibaria both in vitro and in vivo. A reduction in Candida albicans was seen among an elderly population after consuming cheese containing L. rhamnosus GG and Propionibacterium freudenreichii ssp.

Although many researchers anticipate similar mechanisms of action seen with gastrointestinal indications, it is important to note that the microflora, chemical excretions and epithelial structure of the gut differ from those in the mouth and saliva. Currently, there are no commercial oral probiotics available, but some companies are conducting research and development on the use of oral probiotics as a “passive immunization” against oral disease.