Do probiotic bacteria improve human oral microbiota

The term •eprobiotics•f is defined as •eliving microorganisms that exhibit beneficial effects for health based on improvement of balance of indigenous microbiota.•f Several strains of Lactobacillus and Bifidobacterium, and a certain yogurt are included in this definition. Probiotics have been developed for use in the prevention of intestinal infections, and the treatment of antibiotic-associated diarrhea and intestinal malfunction. Recently, the use of probiotics has come to exert a wide range of different effects such as the suppression of Helicobacter pylori, and the prevention of allergic disease. Moreover, evidence for the clinical effectiveness of probiotics has been reported in their use for the prevention and treatment of dental caries and periodontal diseases. For example, the administration of a dairy product containing L. rhamnosus appeared to reduce the risk of dental caries in a randomized, double-blind, placebo-controlled trial. This trial demonstrated reduced levels of dental caries and lower mutans streptococcal counts in probiotics patients after seven months of administration. From the viewpoint of periodontal diseases, it has been suggested that L. salivarius decrease the risk of periodontal disease by eliminating black-pigmented anaerobic rods (BPARs) which have been suspected of playing a role in periodontal disease. Yogurt may suppress the number of mutans streptococci in saliva and improve halitosis. However, there is little available information about the use of probiotics in dentistry. In addition, the role of indigenous Lactobacillus and Bifidobacterium on oral health, the adhesion of probiotics in the human oral cavity, and the mechanisms of probiotics against cariogenic and periodontopathogenic bacteria have not been clarified. In this review, the authors would like to address the possible use and problem of probiotics in dentistry.