Metagenomic Study on Microbial Communities in Deep Caries of Permanent Teeth

doi:10.13701/j.cnki.kqyxyj.2025.09.006

Abstract

Abstract: Objective: To investigate the spacial distribution characteristics of microbial communities in the enamel and deep dentin layer of deep carious lesions in permanent molars based on 16S rRNA high-throughput sequencing, and to analyze the correlation between microbial community variations and the deep caries. Methods: Sixteen adult patients with deep carious lesions in permanent molars were enrolled. Samples were collected from three distinct sites: the enamel layer of the deep carious lesions (EL, n=16), the deep dentin layer (DL, n=16), and the plaque from sound enamel surfaces of contralateral caries-free homologous teeth as healthy layer controls (HL, n=16), yielding a total of 48 samples. Following DNA extraction and the polymerase chain reaction (PCR), 16S rRNA high-throughput sequencing was performed. Then comparative analyses of microbial diversity, community structure, microbial composition, and predicted functional pathways among three groups were conducted. Results: Compared to the HL group, microbial diversity was significantly lower in both EL and DL groups, with the DL group showing the most pronounced reduction (P<0.05). Significant differences in microbial community structure were observed among three groups, with DL the highest degree of similarity and conservation (P<0.05). The analysis identified several health-associated bacteria that were highly expressed in the HL group (P<0.05), along with putative cariogenic bacteria that were specifically enriched in either the EL or DL groups (P<0.05). The EL group showed significant enrichment in genes related to sugar biosynthesis and metabolism (P<0.05), while the DL group exhibited enrichment in genes associated with carbohydrate metabolism and lipid metabolism (P<0.05) when compared to the HL group. Conclusion: These findings highlight the tissue-dependent stratification patterns of microbial communities in deep caries, suggesting that future research on caries pathogenesis should focus on the specific microenvironment of specific dental tissues within individual teeth. The study provides novel insights into the microbial etiology of dental caries.

Key words: deep caries, dental plaque microbiota, metagenomics

LU Guanfan, YANG Jiazhen, SANG Zhiqin, YANG Yu'e, SUN Degang, TENG Fei. Metagenomic Study on Microbial Communities in Deep Caries of Permanent Teeth[J]. Journal of Oral Science Research, 2025, 41(9): 767-772.

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