Abstract
There is a growing interest in using sweeteners for taste improvement in the food and drink industry. Sweeteners were found to regulate the formation or dispersal of structural components of microbial biofilms. Dietary sugars may enhance biofilm formation and facilitate the development of antimicrobial resistance, which has become a major health issue worldwide. In contrast, bulk and non-nutritive sweeteners are also beneficial for managing microbial infections. This review discusses the clinical significance of oral biofilms formed upon the administration of nutritive and non-nutritive sweeteners. The underlying mechanism of action of sweeteners in the regulation of mono- or poly-microbial biofilm formation and destruction is comprehensively discussed. Bulk and non-nutritive sweeteners have also been used in conjunction with antimicrobial substances to reduce microbial biofilm formation. Formulations with bulk and non-nutritive sweeteners have been demonstrated to be particularly efficient in this regard. Finally, future perspectives with respect to advancing our understanding of mechanisms underlying biofilm regulation activities of sweeteners are presented as well. Several alternative strategies for the application of bulk sweeteners and non-nutritive sweeteners have been employed to control the biofilm-forming microbial pathogens. Gaining insight into the underlying mechanisms responsible for enhancing or inhibiting biofilm formation and virulence properties by both mono- and poly-microbial species in the presence of the sweetener is crucial for developing a therapeutic agent to manage microbial infections.
Summary
This review aimed to examine the clinical significance of oral biofilms formed in response to caloric sweeteners, bulk sweeteners, and low/no-calorie sweeteners (LNCS).
Dietary sugars are fermented by oral microbes into organic acids, which promote the growth of cariogenic bacteria such as Streptococcus mutans, Actinomyces, and Lactobacillus. A shift towards cariogenic species lowers the pH within the biofilm formed by oral bacteria to adhere to tooth surfaces, ultimately causing tooth demineralization and, eventually, dental caries. Dietary sugars also facilitate these bacteria’s production of extracellular polymeric substances (EPS), which help in tooth adhesion, accelerate biofilm formation, and provide protection against external stress and antimicrobial agents.
Unlike dietary sugars, bulk sweeteners and LNCS cannot be fermented by oral bacteria, and are therefore not cariogenic. Additionally, they cannot be used by cariogenic bacteria as substrates for biofilm matrix synthesis, resulting in reduced biofilm formation. They also inhibit biofilm- and virulence-related gene expression, leading to a biofilm with lower polysaccharide content and reduced cariogenic potential. As a result, these sweeteners and LNCS are considered non-cariogenic.
Due to these properties, low/no calorie sweeteners are increasingly being employed in a variety of food and hygiene products, as well as drug formulations. In the latter, they have been used together with antimicrobial substances to further reduce microbial biofilm formation.