Sucrose substitutes affect cariogenic potential of S. mutans biofilms

• Grant number: 13/15371-4
• Support Opportunities: Regular Research Grants - Publications - Scientific article
• Start date: December 01, 2013
• End date: May 31, 2014
• Field of knowledge: Health Sciences - Dentistry - Social and Preventive Dentistry
• Principal Investigator: Maria Regina Lorenzetti Simionato
• Grantee: Maria Regina Lorenzetti Simionato
• Host Institution: Instituto de Ciências Biomédicas (ICB). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Streptococcus mutans is considered the primary etiologic agent of dental caries and it contributes significantly to the virulence of dental plaque especially in the presence of sucrose. To avoid the role of sucrose on virulence factors of S. mutans, sugar substitutes are commonly consumed because they lead to lower or no production of acids and interfere with biofilm formation. This study aimed to investigate the contribution of sugar substitutes in the cariogenic potential of S. mutans biofilms. Thus, in the presence of sucrose, glucose, sucralose and sorbitol the mass of biofilm was quantified up to 96 hours, the pH of the spent culture media was measured, the expression of biofilm-related genes were determined, and demineralization challenge experiments were also conduct in enamel fragments. The presence of sugars or sugar substitutes affected profoundly the expression of spaP, gtfB, gtfC, gbpB, ftf, vicR and vicX in either biofilm or planktonic cells. The substitution of sucrose induced a down-regulation of most genes involved in sucrose-dependent colonization in biofilm cells. When the ratio between the expression of biofilm and planktonic cells was considered, most of those genes were down-regulated in biofilm cells in the presence of sugars and up-regulated in the presence of sugar substitutes. However, sucralose but not sorbitol fulfilled the purpose of reducing the cariogenic potential of the diet since it induced the biofilm formation with the lowest biomass, did not change the pH of the medium and led to the lowest lesion depth in the cariogenic challenge. (AU)