Preliminary Microecological Analysis Of Carious Plaque From High Risk School-age Children In Xinxiang City

ObjectiveHigh throughput sequencing technology was used to explore the microecological characteristics of carious plaque from high risk school-age children,and the characteristics and possible influencing factors of dental plaque in the occurrence of dental caries in school-age children were further explored from the microecological perspective of plaque samples.This would provide a more in-depth theoretical basis for the prevention and treatment of dental caries in school-age children.MethodsCaries status examination and questionnaire survey were carried out among 576 school-age children aged 7-11 years in a rural primary school in Weihui County,Xinxiang City,and a total of 36 children with high risk of caries?HC group?and 10 children without caries?CF group?were selected.Dental plaque from sound teeth?HC_S?and carious cavities?HC_C?in HC group and that from teeth in CF group were collected.DNA was extracted from the plaque samples in the laboratory,and the Illumina MiSeq pyrosequencing platform was adopted to perform targeted amplification and sequencing of the V3-V4 gene hypervariable region of the 16S rDNA of the plaque samples.The results of sequencing were used to compare and analyze the microecological characteristics of the plaque samples,such as Alpha diversity,microbial composition,network analysis on relationship among bacteria genera,and biological functional characteristics,so as to explore the bacterial plaque community structure and diversity.Environmental Factor Correlation Analysis?RDA analysis?was conducted on the sequencing data to explore the possible impact of oral health related habits on microecological properties of the dental plaque.Statistically significant level was set at ?=0.05.ResultsA total of 643 microorganisms representing 24 phyla,44 classes,116 orders,186 families,and 367 genera were detected in all plaque samples.The diversity and uniformity of bacteria in carious plaque?HC_C group?were lower than those in HC_S and CF group?P<0.05?,and the species in the HC_C group were more complex and close,with the positive connections significantly increased and the negative connections decreased.Different individuals had different microbial compositions,and the microbial composition of different sampling sites of the same individual was also different.The contents of Streptococcus,Actinomyces,Olsenella,Prevotella,Prevotella₂ and Prevotella₇ were relatively high in the HC_C group?P<0.05?.In terms of functional activities,carbohydrate transportation&metabolism in the HC_C group was higher than that in the HC_S and CF groups.Among the influencing factors in daily life,the carbonated beverages intake and bedtime snacks had a significant effect on the composition and structure of plaque microorganisms?P<0.05?,and the higher the frequency of carbonated beverages intake or bedtime snacks consumption,the higher the content of caries-related microorganisms and the lower the content of health-related microorganisms,which promoted the transformation of the composition of plaque microorganisms towards caries.ConclusionsIn this study population,the individual variability of microorganism composition among school-age children with high risk of dental caries increased.The occurrence of caries was accompanied by a decrease in the diversity and uniformity of plaque microorganisms,and the synergy between species was enhanced,the carbohydrate transportation&metabolism was increased,and the acid production capacity was enhanced.Certain bacteria,such as Prevotella,might be a marker for early detection of dental caries in school-age children.Dietary habits such as carbonated beverages intake and bedtime snacks were significantly correlated with the status of carious plaque in school-age children with high risk of caries.