Isolation and characterization of probiotic strains for improving oral health

Probiotics have been proven effective for preventing caries. In contrast, the effect of probiotics on improving oral diseases such as gingivitis, periodontitis and halitosis has been less explored. Objective: To perform a screening of lactic acid bacteria, according to international guidelines for the evaluation of probiotics, in order to select candidate probiotic strains for preventing oral disorders. Study design: The strains were isolated from healthy children and were subjected to a variety of in vitro tests in order to show their functionality. The safety of the strains was assessed by determining antibiotic susceptibility and production of lactic acid. Results: Forty-six of the 100 new isolates were assigned to lactic acid bacteria genera after a biochemical characterization. Most of the new isolated strains seem to be resistant to oral conditions, have great ability to form aggregates and have high antagonistic activity against oral pathogens. None of the strains produced unpleasant volatile compounds. The strains showed high ability to adhere to oral tissues and they do not present any antibiotic resistance. Moreover, an increased risk of developing caries due to their ability to produce lactic acid was discarded in seven pre-selected probiotic candidates. Conclusions: These lactic acid bacteria show promising properties to be used as potential probiotics for improving oral health. (C) 2011 Elsevier Ltd. All rights reserved.