Sequencing Analysis On Plaque Biofilm Microbial Diversity In Children Aged 12 Months And Their Mothers With Or Without Dental Caries

Objectives: To characterize the composition of supragingival plaque biofilm microbiota in children aged 12 months and their mothers with or without dental caries and analyze the relationship of plaque biofilm microbial diversity between children aged 12 months and their mothers using sequencing analysis.Methods: 20 pairs of mothers and children aged 12 months(10 for dental caries mothers with their 10 children and 10 for caries-free mothers with their 10 children)were included in this study.Questionnaire survey was conducted to collect sociodemographic data and oral health related behaviors for children and their mothers.Pooled supragingival plaque biofilm samples were collected from all the 20 pairs of mothers and children.Plaque biofilm DNA was extracted,used to generate DNA amplicons of the V4-V5 hypervariable region of the bacterial 16 S r RNA gene,and subjected to Mi Seq sequencing system.Results: The results showed no significant differences in socio-demographic background and oral health related behaviors for children and their mothers.Depth,Good’s coverage and sample size of sequencing were reasonable.High bacterial diversity was noted in the plaque biofilm of children and their mothers with or without dental caries(dental caries mother vs.caries-free mother: 774 operational taxonomical units(OTUs)at 3% cutoff vs.761 OTUs at 3% cutoff;children whose mothers have dental caries vs.children whose mothers are caries-free: 815 OTUs at 3% cutoff vs.684 OTUs at 3% cutoff).The Shannon microbial diversity index showed no statistically significant differences both on children and their mothers between two groups(p>0.05).Mother’s microbial diversity was higher than children’s based on Shannon index(p<0.05).Similar results were found in Principal Component Analysis(PCA)analysis.Significant positive correlations were found between mothers’ and their children’ Shannon microbial diversity index(r=0.656,p=0.002).Microbial community structure analysis revealed 18 predominant bacteria by genus occupied the majority of oral microbiota.Network of species correlation analysis by genus showed positive correlations between species.No significant cluster related with exposure and control group were found in cluster-analysis.Conclusion: This study shows that mother’s oral microbial diversity have an overall impact on the children aged 12 months.These findings might be extended to a more scientific basis for microbial factors of early childhood caries risk assessment.