Reasearch Of Caries Related Oral Microbial Structure And Salivary Proteome In6-8Years Old Children From "Isolated Population"

Background: As a special bacterial infectious diseases,caries is lack ofself-limiting and can cause serious consequences. Bacterial factors(dentalplaque) is thought to be initial factors in the development of caries,andcaries related oral microbial structures is very complex.To date, most of the oral microbial structure studies indicate that humanoral cavity may exist a "core microbiome". At the same time,verifyingwhether or not there was a “core oral microbiome” is one of humanmicrobiome projec’s purpose.In addition, the salivary proteome also has the potential to promote orprevent tooth decay. At the same time, oral proteome are potential sourcesof proteinic biomarkers todiagnosis and preventionof local and systemdisease. So the appeal,systematically explore oral proteome and microbialdiversity should help to the cognition,prevention and treatment of localand system disease such as dental caries.Objective: Analyzing and comparing the microbial function(preteome)and diversity in saliva and dental palque between caries group and healthy group.First,to explore the microbial structure and difference between thetwo group from several taxonomic levels such as phyla, class, order,family,genera, species, and to verify whether or not there was a “core oralmicrobiome”.Second,to explore the relationship of the saliva proteomewith caries, further to push related biomarkers studies of cariessusceptibility.Methods: caries children and healthy children were sampled and assignedinto two groups.First, analyze and compare the microbial diversity insaliva and dental palque between caries group and healthy group with16SrDNA sequencing (Part1). Second, analyze and compare the proteomefrom saliva between caries group and healthy groupwithHPLC-MS/MS(Part2).Results:Part1:.(1) This experiment produced more than6000OTU per sample, fora total of14076OTU, belong to18phyla,28classes,48orders,78families,133genera.In the results, the caries group produced9265OTU (cariesplaque6042OTU, caries saliva5406OTU), and the healthy groupproduced10080OTU (healthy plaque6757OTU, caries saliva5661OTU).(2) A total of15differential genera have statistically significantdifference (p <0.05) between caries plaque and healthy plaque, including10genera have higher detectable rate in caries plaque and5genera havehigher detectable rate in healthy plaque, the differential genera are: Actinomyces,Bergeyella,Capnocytophaga,Cardiobacterium,Derxia,Granuli-catella, Haemophilus, Kingella, Megasphaera, Mogibacterium, Moraxella,Neisseria, Slackia.(3) A total of17differential genera have statisticallysignificant difference (p <0.05) between caries saliva and healthy saliva,including11genera have higher detectable rate in caries saliva and5genera have higher detectable rate in healthy saliva, the differential generaare: Acholeplasma, Acinetobacter, Actinobaculum, Alysiella, Butyrivibrio,Delftia, Derxia, Dialister, Haemophilus, Lactobacillus, Porphyromonas,Propionivibrio, Pseudoramibacter, Streptobacillus etc.(4)There existed27common genera through10caries plaque samples and10healthy plaquesamples,they were: Abiotrophia, Actinomyces,Aggregatibacter,Bergeyella,Campylobacter, Capnocytophaga, Comamonas, Corynebacterium, Derxia,Eikenella, Fusobacterium, Gemella, Granulicatella, Johnsonella, Kingella,Leptotrichia, Neisseria, Paludibacter, Porphyromonas, Prevotella,Propionibacterium, Streptococcus, Tannerella, Treponema, Veillonella etc.And there existed24common genera through10caries saliva samples and10healthysalivasamples,theywere:Abiotrophia,ctinomyces,Bergeyella,Campylobacter,Capnocytophaga,Catonella,Corynebacterium,Derxia,Fusob-acterium,Gemella,Granulicatella,Johnsonella,Leptotrichia,Neisseria,Oribac-terium,Peptostreptococcus,Porphyromonas,Prevotella,Propionibacterium,Rothia,Selenomonas,Streptococcus,Veillonella.(5)Recognizedcariogenic bacteriasuch as streptococcus mutans, negroponte actinomycetes, lactobacillus etc had detection to varying degrees in each sample, and their differencesbetween caries group and healthy group were diverse from each other.Part2:Finally we got quantitative information of1626human protein fromthis experiment, and the differential protein count between caries saliva andhealthy saliva was642, including MMP9,MUC7,LTF,CA6,AZU andColdagglutinin etc which may have some relationship with caries.Conclusions:(1) veillonella can cause caries and its specific role needfurther research and verification.(2)capnocytophaga were negativelyrelated with caries in dental plaque, and were positively correlated withcaries in saliva，so its constituent ratio can be used as potential monitoringindex of caries susceptibility.(3)There was no appearance that microbialstructure of each two samples werecompletely different, and somemicrobes were are checked out in all plaque samples (or saliva samples),theresult above supportedthe existence of common oral coremicrobiome.(4)The total salivary protein in caries group was higher thanthat of healthy group,and the differential proteins which may have somerelationship with caries containing MMP9,MUC7, LTF,CA6,AZU andColdagglutinin etc,and these results may lay some foundation of deeperbiomarker research of dental caries susceptivity.