Differences in carbon source usage by dental plaque in children with and without early childhood caries

Early childhood caries (ECC) is a considerable pediatric and public health problem worldwide. Preceding studies have focused primarily on bacterial diversity at the taxonomic level. Although these studies have provided significant information regarding the connection between dental caries and oral microbiomes, further comprehension of this microbial community’s ecological relevance is limited. This study identified the carbon source metabolic differences in dental plaque between children with and without ECC. We compared the microbial community functional diversity in 18 caries-free subjects with 18 severe ECC patients based on sole carbon source usage using a Biolog assay. The anaerobic microbial community in the ECC patients displayed greater metabolic activity than that of the control group. Specific carbon source metabolism differed significantly between the two groups. Subjects from the two groups were well distinguished by cluster and principal component analyses based on discriminative carbon sources. Our results implied that the microbial functional diversity between the ECC patients and healthy subjects differed significantly. In addition, the Biolog assay furthered our understanding of oral microbiomes as a composite of functional abilities, thus enabling us to identify the ecologically relevant functional differences among oral microbial communities. Bacteria in dental plaque from children with early childhood caries metabolize carbon from different sources than bacteria from healthy individuals. Early childhood caries (ECC) is the most common chronic disease in children. Scientists from the Peking University School and Hospital of Stomatology led by Feng Chen and Yunsong Liu, compared the oral microbe populations of 18 ECC patients and 18 caries-free children. The team found that bacteria in plaque from ECC patients preferred certain sugars and carbohydrates as carbon sources, whereas bacteria from healthy subjects preferred certain amino acids and short protein chains. Analysis showed that anaerobic bacteria in ECC patients exhibited greater metabolic activity than those from the caries-free group. This study indicates that metabolic profiles could act as ‘signatures’ of disease states, and that further studies might suggest carbohydrates for ECC-susceptible children to avoid.