Project description:Childhood caries is an extremely common childhood chronic disease, affecting 60–90% of children in industrialized countries. It results in lesions in both the primary and permanent dentitions, hospitalizations and emergency room visits, high treatment costs, loss of school days, diminished ability to learn increases the risk of caries in adulthood. Streptococcus mutans is a key bacteria in caries development. While multiple caries risk factors have been identified, significant interpersonal variability not explained by known risk factors still exists. The immune system generates a personal antibody repertoire that helps maintain a balanced and healthy oral microbiome. Using mass-spectrometry, we probed in an hypothesis-free manner which S. mutans proteins are identified by antibodies of children with low and high DMFT (decayed, missing, filled teeth) scores. We identified a core set of proteins, recognized by the immune system of most individuals. This set was enriched with proteins enabling bacterial adhesion, and included glucosyltransferases and glucan-binding proteins known to be important for S. mutans cariogenicity. To explore the physiological relevance of these findings, we tested the ability of saliva from caries free individuals in preventing S. mutans from binding to the tooth surface. Indeed, saliva from individuals with caries free prevented S. mutans binding to teeth. These findings map the S. mutans proteome targeted by the immune system and suggest that inhibiting tooth attachment is a primary mechanism used by the immune system to maintain oral balance and prevent caries. These findings provide new insights into the role of the immune system in maintaining oral health and preventing caries development.
Project description:Human saliva microbiota is phylogenetically divergent among host individuals yet their roles in health and disease are poorly appreciated. We employed a microbial functional gene microarray, HuMiChip 1.0, to reconstruct the global functional profiles of human saliva microbiota from ten healthy and ten caries-active adults. Saliva microbiota in the pilot population featured a vast diversity of functional genes. No significant distinction in gene number or diversity indices was observed between healthy and caries-active microbiota. However, co-presence network analysis of functional genes revealed that caries-active microbiota was more divergent in non-core genes than healthy microbiota, despite both groups exhibited a similar degree of conservation at their respective core genes. Furthermore, functional gene structure of saliva microbiota could potentially distinguish caries-active patients from healthy hosts. Microbial functions such as Diaminopimelate epimerase, Prephenate dehydrogenase, Pyruvate-formate lyase and N-acetylmuramoyl-L-alanine amidase were significantly linked to caries. Therefore, saliva microbiota carried disease-associated functional signatures, which could be potentially exploited for caries diagnosis. The DMFT INDEX (Decayed, Missing, Filled [DMF] teeth index used in dental epidemiology) values are provided for each sample We employed a microbial functional gene microarray, HuMiChip 1.0, to reconstruct the global functional profiles of human saliva microbiota from ten healthy and ten caries-active adults.
Project description:Human saliva microbiota is phylogenetically divergent among host individuals yet their roles in health and disease are poorly appreciated. We employed a microbial functional gene microarray, HuMiChip 1.0, to reconstruct the global functional profiles of human saliva microbiota from ten healthy and ten caries-active adults. Saliva microbiota in the pilot population featured a vast diversity of functional genes. No significant distinction in gene number or diversity indices was observed between healthy and caries-active microbiota. However, co-presence network analysis of functional genes revealed that caries-active microbiota was more divergent in non-core genes than healthy microbiota, despite both groups exhibited a similar degree of conservation at their respective core genes. Furthermore, functional gene structure of saliva microbiota could potentially distinguish caries-active patients from healthy hosts. Microbial functions such as Diaminopimelate epimerase, Prephenate dehydrogenase, Pyruvate-formate lyase and N-acetylmuramoyl-L-alanine amidase were significantly linked to caries. Therefore, saliva microbiota carried disease-associated functional signatures, which could be potentially exploited for caries diagnosis. The DMFT INDEX (Decayed, Missing, Filled [DMF] teeth index used in dental epidemiology) values are provided for each sample
Project description:Our group recently transcriptomically characterized coculture growth between Streptococcus mutans and several species of commensal streptococci (Rose et al, 2023). However, these experiments were carried out in our lab-based experimental medium, tryptone and yeast extract (TY-). To understand whether culturing these species within a medium that more closely mimics their natural environment alters the interaction, we evaluated both monoculture and coculture growth between the dental caries pathogen Streptococcus mutans and oral commensal species Streptococcus oralis in a half TY- / half human saliva mix that was optimally chosen based on our initial characterization of oral streptococci behaviors in medium mixes containing saliva. Our results surprising show that inclusion of saliva enhances the competition of Streptococcus mutans against commensal streptococci through upregulation of carbohydrate uptake and glycolytic pathways.