Discovery, biological evaluations, and modified applications of peptide AVHS derived from dental plaque biofilms.

With the growing prevalence of early childhood caries (ECC), there is an urgent need to develop effective strategies for caries prevention. Investigation of oral metabolomic microenvironments among caries-free children could provide valuable insights. Therefore, this study aims to identify a "dominant metabolite" from plaque biofilms in children with varying levels of dental caries and to assess the biological attributes of this metabolite. A case-control study, combined with untargeted metabolomics, was conducted among three groups: caries-free (CF), low ECC (LECC), and high ECC (HECC). Then, the biological properties of this "dominant metabolite" were evaluated by biocompatibility analysis, bacterial growth and acid production assessment, biofilm targeting and remineralization test. This "dominant metabolite" was conjugated with a known antibacterial peptide Arg-Trp-Trp-Arg-Trp-Trp (RWWRWW), and the caries preventive effect of this compound was evaluated in vitro and in vivo. This study included 102 children aged 36 months. Metabolomic analysis revealed that Ala-Val-His-Ser (AVHS) was the most abundant metabolite in the CF group (P < 0.05), with moderate predictive performance (AUC = 0.675). AVHS has good biocompatibility; it can slow down the growth and acid production of Streptococcus mutans and effectively target plaque biofilm. The AVHS@RWWRWW conjugate exhibited superior antibiofilm effects in vitro and significantly reduced caries in rats than in the control group (P < 0.05). In conclusion, AVHS not only exhibits modest predictive performance for healthy children in clinical research but also demonstrates multiple biological functions. AVHS@RWWRWW shows better antibiofilm effect and can promote caries prevention, making it a promising candidate for development as a preventive agent.