Development of an eco-sustainable formulation against Streptococcus mutans and Candida albicans

Abstract

The acidic niche of dental plaque can lead to caries expression over time. In this study, we attempted to design an eco-sustainable oral care formulation, and to determine its effect on caries-related pathogens in the presence and absence of lactic acid. We investigated the inhibitory effect of slightly acidic electrolyzed water (SAEW) combined with sodium benzoate (NaB) on the growth of caries-related microorganisms (both bacteria and fungi). SAEW’s antimicrobial activity was significantly increased in the presence of lactic acid (4.0 log CFU/mL for Streptococcus mutans, and 5.31 log CFU/mL for Candida albicans). In the presence of lactic acid, 0.1% of NaB completely inhibited the growth of Streptococcus mutans and Candida albicans, while there was no significant inhibitory effect in the absence of lactic acid. The results showed that SAEW combined with NaB had high antimicrobial activity in the acidic environment but low efficacy in the normal niche. Thus, this combination may have fewer negative effects on oral microbiota diversity. This is the first study to investigate the possibility of SAEW as alternatives to alcohol-based oral hygiene products.