In vitro and in vivo anti-microbial activity evaluation of inactivated cells of Lactobacillus salivarius CECT 5713 against Streptococcus mutans

摘要

Highlights ? Heat-inactivated cells of Lactobacillus salivarius CECT 5713 inhibits Streptococcus mutans adhesion to hydroxyapatite. ? Inhibitory effect seems not to be an unspecific phenomenon. ? Its use as mouthwash reduce the Streptococcus mutans in saliva. Abstract Objective Defining the etiology of dental caries is a complex problem. The microbiological approach has included Streptococcus mutans as one of the bacterial species involved in this disease. This research investigates the inhibitory effects of heat-inactivated Lactobacillus salivarius CECT 5713 against S. mutans using in vitro and in vivo assays. Design On the one hand, the effect of non-viable L. salivarius CECT 5713 on the in vitro adhesion of S. mutans to hydroxyapatite discs was evaluated. On the other hand, levels of Streptococcus mutans , amount of salivary flow and salivary pH before and after taking the rinse with the non-viable L. salivarius CECT 5713 in healthy volunteers were assessed (self-controlled open-label pilot study). Results The levels of S. mutans seemed to decrease in the in vitro and in vivo assays (p in vitro effect of non-viable L. salivarius was maintained until 36 months of storage. In addition, the reduction of S. mutans salivary concentration in the volunteers was statistically significant from the third day until two weeks of treatment. Conclusions Heat-inactivated L. salivarius CECT 5713 prevents S. mutans adhesion to hydroxyapatite and could be used as a strategy to reduce the salivary concentration of this oral pathogen.