Effect of rubusoside, a natural sucrose substitute, on the metabolism of Scardovia wiggsiae: a novel potential cariogenic pathogen

Abstract

Abstract Background Intake of glucose and sucrose accelerates the development of dental caries in children. Scardovia wiggsiae (S. wiggsiae) is a potential pathogen of early childhood caries (ECC). Previous research conducted by our group has demonstrated that rubusoside, a non-cariogenic sweetener, inhibits the caries pathogen Streptococcus mutans (S. mutans). To investigate the effects of rubusoside as a sucrose substitute and sweet additive on the growth and metabolism of S.wiggsiae and to predict the underlying mechanisms. Results The minimum inhibitory concentration (MIC) of rubusoside was determined to be 1% using the microdilution method. Both as a standalone agent and in combination with sucrose, rubusoside significantly inhibited the growth, acid-producing capability, and adhesion of S.wiggsiae. Utilizing techniques such as crystal violet staining, anthrone-sulfuric acid reaction, BCA protein quantification, scanning electron microscopy (SEM), and confocal laser scanning microscopy (CLSM), we demonstrated that rubusoside effectively suppressed the formation of S. wiggsiae biofilms and reduced the synthesis of extracellular polysaccharides (EPS) and soluble proteins. The whole genome sequencing of S. wiggsiae was conducted for the first time and combined with RNA-seq analysis, the potential mechanism of rubusoside inhibiting bacterial biofilm formation was predicted: It might exert bacteriostatic effects by influencing bacterial carbohydrate metabolic pathways (such as nucleotide sugar synthesis, amino sugar and nucleotide sugar metabolism, galactose metabolism, and phosphotransferase system), and downregulating the expression of virulence genes (clpP and groEL) related to adhesion, invasion, and biofilm formation. Conclusions Rubusoside exhibits a significant bacteriostatic effect against S. wiggsiae, a potential pathogen associated with early childhood dental caries. Notably, its inhibitory activity remains unaffected even in the presence of sucrose. Consequently, as a sucrose substitute or sweetener additive, rubusoside holds broad application prospects in both the food industry and oral hygiene products, offering a promising approach to the prevention and treatment of dental caries.

Keywords

• Rubusoside
• Scardovia wigggsiae
• Early childhood caries
• RNA sequencing
• Metabolism