Anti adhesive effect of Lactobacillus rhamnosus as a probiotic on oral Streptococci

Dental caries, caused mainly by mutans Streptococci, is the most common chronic disease in the world. Employment of probiotics is a new emerged technique to prevent dental caries production, and Lactobacillus rhamnosus is one of the important common probiotics in this strategy. This study aimed to evaluate the effects of L. rhamnosus on the adhesion of oral Streptococci. This cross-sectional study was carried out on 40 isolates of mutans and non-mutans Streptococci isolated from dental plaque and caries of the volunteers who admitted in dental school of Islamic Azad University, Khorasgan. The biofilm formation ability of these strains was investigated and the strongest isolates in this term were selected. The effect of L. rhamnosus (ATCC4769) on the adhesion of Streptococci was investigated by several methods; 1: an equal volum of Lactobacillus and Streptococcus, 2: application of Lactobacilli 30 minutes before induction of Streptococci into the system, 3: probiotic pellet 4: a supernatant of the overnight culture of probiotic. Overall, L. rhamnousus led to reduction of Streptococci adhesion to surface using all four strategies. The second method was the most effective, its effect was more efficient on S. mutans adhesion than non-mutans. There was no significant difference between third and fourth methods, but effect of both methods on S. mutans was more than other Streptococci. Application of L. rhamnousus as probiotic could reduce the adhesion of mutans and non-mutans Streptococci to dental surfaces and therefore can reduce dental decay.