Microbiology insights into boosting salivary defences through the use of enzymes and proteins

Abstract

Objectives: To assess the effects of enzymes and proteins in toothpastes to boost salivary defences and reduce oral bacteria growth and viability.

Methods: An in vitro study to measure levels of hypothiocyanite in saliva after treatment with a toothpaste containing enzymes and proteins (colorimetric assay). A randomised, crossover in vivo study measuring, with biochemical assays, the effect of a toothpaste containing enzymes and proteins on the levels of hydrogen peroxide and lysozyme in saliva. In vitro studies to measure, using fluorescent dyes, the effects of enzymes and proteins on bacterial membrane integrity. In vitro microbiology studies measuring the effects of enzymes and proteins on planktonic bacterial growth, in vitro studies in single and multispecies biofilms measuring the effect of toothpaste with enzymes and proteins compared to control toothpaste.

Results: Levels of hypothiocyanite, hydrogen peroxide and lysozyme are boosted after application of a toothpaste containing enzymes and proteins. The enzymes and proteins adversely affect the bacterial membrane integrity in Streptococcus mutans and growth of planktonic S. mutans and Fusobacterium nucleatum. In a single species biofilm model the viability of S. mutans was significantly reduced and in a 7 species biofilm model bacterial viability was reduced for a biofilm grown on a pellicle pre-treated with toothpaste containing enzymes and proteins.

Conclusions: The use of a toothpaste containing enzymes and proteins can boost the natural salivary defences by increasing the levels of lysozyme and hydrogen peroxide in vivo and hypothiocyanite in vitro and reduce the growth and viability of oral bacteria in microbiological models.

Clinical significance: The subtle effects reported here of enzymes and proteins in toothpastes on oral bacteria are consistent with both the gum health benefits reported for such toothpastes containing enzymes and proteins by Daly [1] and Pedersen [2] and the rebalancing of the oral microbiome reported by Adams [3].

Keywords: Amyloglucosidase; Glucose oxidase; Lactoferrin; Lactoperoxidase; Lysozyme; Toothpaste.