Investigation of the oral microbiome of children associated with dental caries: A systematic study.

OBJECTIVE: The present study aims to investigate the variations in dental caries (DC) related microbiome abnormality and metabolomics shift in children. DESIGN: The patients were divided into two groups healthy control (C) and highly affected DC children based on inclusion and exclusion criteria. Saliva samples were collected and used for the taxonomic and functional characterization of oral microbiota. RESULTS: Metatranscriptomics analysis revealed the alterations and composition of oral microbiota in the C and DC groups. Relative abundance in the C group was associated with Firmicutes, Actinobacteria, and Bacteroidetes. Whereas, the microbial composition in the DC group was found to be considerably altered with increases in the abundance of the Proteobacteria (25%), Fusobacteria (15%), and Cyanobacteria (8%) while decreases in the abundance of Firmicutes (10%) and Bacteroidetes (23%). Alterations in the phylum composition were positively and negatively correlated with several metabolites of sugars (such as fructose, sorbose, ribose, allose, and mannose) and amino acids (such as arginine, lysine, tryptophan, and proline). Moreover, in comparison with the C group, the metabolic shift of the DC group was different with an increase in certain tricarboxylic acid cycle intermediates levels, and a decrease in fatty acid. Such alterations can enhance the growth of oral pathogens and contribute to DC development. CONCLUSIONS: The findings of this study suggest that an altered abundance of Actinobacillus, Fusobacterium, and Shuttleworthia can serve as biomarkers of DC in children.