Inhibitory effects of Stevioside on Streptococcus mutans and Candida albicans dual-species biofilm

Abstract

IntroductionStreptococcus mutans is the most prevalent biofilm-forming pathogen in dental caries, while Candida albicans is often detected in the presence of S. mutans.MethodsWe aimed to evaluate the anti-caries effect of stevioside in medium trypticase soy broth (TSB) with or without sucrose supplementation compared with the same sweetness sucrose and xylitol in a dual-species model of S. mutans and C. albicans, based on planktonic growth, crystal violet assay, acid production, biofilm structural imaging, confocal laser scanning microscopy, and RNA sequencing.ResultsOur results showed that compared with sucrose, stevioside significantly inhibited planktonic growth and acid production, changed the structure of the mixed biofilm, and reduced the viability of biofilm and the production of extracellular polysaccharides in dual-species biofilm. Through RNA-seq, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway impact analysis showed that stevioside decreased sucrose metabolism and increased galactose and intracellular polysaccharide metabolism in S. mutans, and decreased genes related to GPI-modified proteins and secreted aspartyl proteinase (SAP) family in C. albicans. In contrast to xylitol, stevioside also inhibited the transformation of fungal morphology of C. albicans, which did not form mycelia and thus had reduced pathogenicity. Stevioside revealed a superior suppression of dual-species biofilm formation compared to sucrose and a similar anti-caries effect with xylitol. However, sucrose supplementation diminished the suppression of stevioside on S. mutans and C. albicans.ConclusionsOur study is the first to confirm that stevioside has anticariogenic effects on S. mutans and C. albicans in a dual-species biofilm. As a substitute for sucrose, it may help reduce the risk of developing dental caries.

Sugar Substitute Stevia Inhibits Biofilm Formation, Exopolysaccharide Production, and Downregulates the Expression of Streptococcal Genes Involved in Exopolysaccharide Synthesis

“…It was found to inhibit the growth and biofilm formation of various bacteria, including S. mutans, Borrelia burgdorferi, Lactobacillus, and coagulase-negative staphylococci [29,37,38]. Furthermore, a study by Guo et al demonstrated the inhibitory effects of stevioside on a dual-species biofilm model of S. mutans and Candida albicans [39], highlighting its potential against fungal species. In addition to inhibiting biofilm formation, stevia has also been shown to reduce EPS production [26,29], suggesting its ability to interfere with the structural integrity and protective properties of biofilms, making them more susceptible to disruption and removal.…”

Alteration of oral microbial biofilms by sweeteners

“…In addition, 10 % acesulfame-K and 7.5 % sucralose inhibited the biofilm formation of Porphyromonas gingivalis , an anaerobic periodontal pathogen, and showed bactericidal activity against bacteria within the biofilm [ 88 ]. Stevioside also inhibited the formation of mixed biofilms of C. albicans and S. mutans and acid production [ 29 ]. Stevioside facilitated the metabolic utilization of galactose and intracellular polysaccharides while reducing that of sucrose.…”

“…Although non-nutritive sweeteners cannot be digested to generate energy, they can be potentially toxic to cells following cellular absorption [ 25 ]. Nevertheless, non-nutritive sweeteners have also been shown recently to be beneficial in managing microbial infections [ [26] , [27] , [28] , [29] , [30] ]. Bulk sweeteners also exhibit antibacterial efficacy against a variety of drug-resistant pathogens [ [31] , [32] , [33] ].…”

Unveiling the complexity of early childhood caries: Candida albicans and Streptococcus mutans cooperative strategies in carbohydrate metabolism and virulence

“…In the quest for sugar substitutes that could prevent for caries, one research has indicated that stevioside significantly inhibits growth and biofilm formation in mixed-species cultures, suggesting its potential as an alternative to sucrose [ 44 ]. Interestingly, the addition of 1% sucrose to these cultures counteracted the inhibitory effects of stevioside, highlighting the importance of reducing sucrose intake for dental caries management [ 44 , 82 ].…”

“…In the quest for sugar substitutes that could prevent for caries, one research has indicated that stevioside significantly inhibits growth and biofilm formation in mixed-species cultures, suggesting its potential as an alternative to sucrose [ 44 ]. Interestingly, the addition of 1% sucrose to these cultures counteracted the inhibitory effects of stevioside, highlighting the importance of reducing sucrose intake for dental caries management [ 44 , 82 ]. Among various commercially available sugar substitutes, stevioside, along with other levorotatory carbohydrates such as xylitol and sorbitol, has demonstrated similar inhibitory effects on the mixed-species biofilm [ 83 ].…”