Microbiota In High-Caries Patients And Cross-Species Biofilm Validation

Screening the core microbiota of high-caries-risk patients and conducting an in vitro study on the cariogenicity of multi-species mixed biofilm. From October 2022 to April 2023, seven adult patients with high caries activity were recruited as the high-caries group. Additionally, six qualifying caries-free participants were enrolled as the control group. Ethical approval was obtained from the Ethical Committee (Ethics NO, NJSH-2022NL-47). Based on microbiome findings, a multispecies biofilm system comprising S. mutans, V. parvula and C. albicans was constructed. Acid production assays, acid and oxygen stress challenges, SEM, live/dead bacterial staining, qPCR, and CLSM were used to evaluate the biological performance of the multispecies mixed biofilm. The detection rate of S. mutans and V. parvula in the saliva of the two groups was 100%, the detection rate of C. albicans in the saliva of high-caries group (71.4%) was higher than that of caries-free group (33.3%). Co-culture of S. mutans with V. parvula and C. albicans enhanced synergistic growth, yielding a denser, less porous multispecies biofilm. GTF expression was significantly higher in the mixed biofilm group compared to all other groups. This study revealed that S. mutans, V. parvula and C. albicans species were enriched in the saliva of high-caries-risk patients. When co-cultured with V. parvula and C. albicans, S. mutans in the biofilms significantly enhanced survival and cariogenic abilities.