Anti-caries Impacts Of Probiotics Powder On Severe Early Childhood Caries

Objective:To study the anti-caries impacts of oral probiotics powder on 5-year-old children with severe early childhood caries,by observing changes in growth of Streptococcus Mutans,pH level of the saliva and plaque biofilm microecology..Methods:A total of thirty 5-year-old children who met the inclusion and exclusion criteria with severe early childhood caries were recruited for this study.The participants were randomly divided into two groups using randomized double-blind controlled method.The participants in experimental group took probiotics powder for 7-days while the others in control group took placebo powder without probiotics during this period.The non-irritating saliva and dental plaque were collected and the following tests were conducted:(1)Colony-counting method was used to count S.mutans in salivary at the baseline,after taking-powder,1-week post-taking-powder,2-week post-taking-powder,1-month post-taking-powder and 3-month post-taking-powder.Salivary pH was recorded at the same time points.Repeated-measures ANOVA was used to analyze data.(2)16S rDNA high-throughput sequencing was used to observe the diversity of the oral microbial community composition in plaque biofilm at baseline and after taking-power.Alpha-diversity,Beta-diversity and OUT based on the sequence similarity was analyzed.Results:(1)Impacts of probiotics powder on growth of Streptococcus Mutans and pH level of the saliva in children with S-ECC:①Impacts on S.mutans in saliva:compared to the baseline,the number of S.mutans in both groups significantly decreased after taking-powder(P<0.05).After 1-week post-taking-powder,the number of S.mutans in the saliva of the two groups increased.But no statistical difference was observed in that of S.mutans between the baseline and after taking-powder(P>0.05).At 2-week post-taking-powder,1-month post-taking-powder and 3-month post-taking-powder(P>0.05),no significant difference was observed between the two groups in the number of S.mutans in the saliva.②Impacts on the pH of saliva:there was no statistical difference in saliva pH between the two groups at the baseline,after taking-powder,1-week post-taking-powder,2-week post-taking-powder,1-month post-taking-powder and 3-month post-taking-powder(P>0.05).(2)Impacts of probiotics powder on microbial community composition and diversity of plaque biofilm in children with S-ECC:2535490 high-quality sequences were obtained from 60 samples,and optimized 2235743 OTUs by Illumina MiSeq.①Impacts on the Simpson Index of the oral microbial flora:comparing to the baseline,there was no significant difference between two groups after taking-powder(P>0.05).②Impacts on the composition of the oral microbial flora:comparing to the baseline,the composition of some bacteria in the plaque biofilm of the two groups changed after taking-powder.At the phylum level,Bacteroidetes,Firmicutes,and Actinobacteria decreased significantly(P<0.05).At the genus level,Acinetobacter,Actinomyces,Alloprevotella,Anaeroglobus,A topobium,Granulicatella,Kingella,Pseudomonas,Selenomonas,Streptococcus,Tannerella,and an Unclassified Veillonellaceae decreased significantly(P<0.05).There was no significant difference in Lactobacillus(P>0.05).③Impacts on the number of the oral microbial flora:comparing to the baseline,the number of some bacteria in the plaque biofilm of the two groups changed after taking-powder At the genus level,Acinetobacter,Pseudomonas,Streptococcus decreased significantly(P<0.05)Conclusion:The 7-day short-term usage of probiotics inhibited the growth of free S.mutans in the saliva of S-ECC children in the 5-year-old group.The inhibition effects gradually disappeared after 1-week post-taking-powder.Consuming probiotics had no significant impacts on the pH level of saliva,while the composition and number of the bacterial flora of the plaque biofilm changed significantly.The bacterial flora structure and diversity of the plaque biofilm did not vary.In order to evaluate the anti-caries impacts of probiotics powder on 5-year-old children,a long-term and further study will be needed.