| ObjectiveTo provide scientific basis for the prevention and treatment of dental fluorosis,the difference of intestinal microecology structure between children with dental fluorosis without dental fluorosis was compared under the same exposure level,and the characteristics of intestinal microecology related to dental fluorosis were explored.MethodsThe morning urine of 105 recruited children aged 8?12 years was collected for the determination of urinary fluorine and urinary iodine in a drinking water-born endemic fluorosis area in Henan Province.And questionnaire survey,examination of dental fluorosis and dental caries were performed.After eliminating the use of antibiotics,intestinal diseases and other factors,children with dental fluorosis and without dental fluorosis were selected from children with urinary fluorine concentration greater than 1.4 mg/L.Fresh stool samples were collected and gut bacterial DNA was extracted.The 16 S rDNA was sequenced by PCR-DGGE and Illumina to compare the structure,composition and possible functional differences of intestinal flora between children with dental fluorosis and normal controls.Results1.A total of 23 subjects were included in this study,including 9 children with dental fluorosis and 14 control children.There were no significant differences in age,gender composition,height,weight,body mass index(BMI),concentrations of urinary fluoride and urinary iodine between the two groups(P values were greater than 0.05).2.The richness index of Alpha diversity index obtained by PCR-DGGE was higher in control group than in dental fluorosis group(P>0.05).Cluster analysis and principal component analysis showed that there was no significant separation between the children in the dental fluorosis group and those in the control group,and there was overlap between them.3.A total of 1046362 high-quality sequences were obtained by Illumina high-throughput sequencing.Then these sequencs were clustered into 2073 OTUs with 97% similarity.Chao 1 richness index,ACE richness,Shannon diversity index and Simpson diversity index of two groups were calculated.The results showed that the above indexes in the control group were higher than those in the dental fluorosis group(P>0.05).4.The principal coordinate analysis and cluster analysis based on Illumina sequencing showed that there was no significant separation of bacterial community structure between the children in the dental fluorosis group and those in the control group,and there were overlaps between them.ANOSIM test showed that the difference between groups was not statistically significant(R=0.01,P=0.41).When comparing the sample dispersion within the group,we found that the intestinal flora dispersion among different individuals in the dental fluorosis group was greater than that in the control group(P>0.05).5.Significant analysis of species difference between groups at the phylum level showed that Acidobacteria was found in the fluorosis group,but the abundance was 0 in the control group(1.44 vs 0,P=0.00).Thermi was only found in children without dental fluorosis group,but whose abundance was 0 in the dental fluorosis group,(0.57 vs 0,P=0.03).At the genus level,a total of 15 species were identified to be different abundance distribution between groups.Compared with the control group,the children of the dental fluorosis group showed a significant increase in Peptococcus,Prevotella and Dehalobacterium(P<0.05).Streptococcus,Ruminococcus,Granulicatella,Acidaminococcus,DA101,Deinococcus,Erwinia,Actinoplanes,Anaerotruncus,Campylobacter and Mycobacterium decreased significantly in dental fluorosis group(P<0.05).6.The functional genes in the intestinal flora of the children in the dental fluorosis group and in the control group were compared by PICRUSt.The results showed that the number of pentose and glucuronate interconversions genes involved in carbohydrate metabolism decreased in the intestinal microbiota of children with dental fluorosis.Conclusions1.The exsistence of Acidobacteria,the absence of Thermi,the increase of the abundance of Peptococcus,Prevotella and Dehalobacterium,and the decrease of the abundance of 12 bacterial genera,including Streptococcus,which may be associated with dental fluorosis of children in this areas.2.The decrease in the number of pentose and glucuronate interconversions genes involved in carbohydrate metabolism in the intestinal flora may be related to the dental fluorosis of children in this areas. |
PDF Full Text Request