研究生英文文献汇报系列2

ContensBackgroundObjectivesMethodsResultsStrengthsandlimitationsConclusions第一页，共32页。

Wordsrodents（啮齿动物）Gutcolonization（肠道微生物定植）MSEL:MullenScalesofEarlyLearning（马伦早期学习量表）16SribosomalRNAampliconsequencing（16srRNA扩增子测序）alphadiversity（α多样性：

α多样性高，肠道菌群比较成熟）theUniversityofNorthCarolinaatChapelHill（北卡罗来纳大学教堂山分校）Co-occurrenceNetworks（共线/同现网络）MetagenomePrediction（宏基因组学预测，利用基因组学的研究策略研究样品所包含的全部微生物的遗传组成及其群落功能）Faecalibacterium（普氏菌）Bacteroides（拟杆菌）Ruminococcaceae（瘤胃球菌/疣微菌科）第二页，共32页。Background第三页，共32页。1.Thegutmicrobiomeisacomplexmicrobialecosystemthatvariesbetweenindividualsandmaybeakeymodulatorofneurodevelopment

throughthemicrobiome-gut-brainaxis（肠脑轴）.2.Inrodents,experimentalmanipulationsthataltertheintestinalmicrobiotaimpactanxietyanddepression-relatedbehaviors.3.Inhumans,alteredmicrobialcompositionoftheguthasbeenreportedinchildrenwithautism

andadultswithdepressionandislinkedtochildhoodtemperamentandadultcognition.第四页，共32页。4.Nostudieshaveaddressedwhentheserelationshipsemergeordirectlyexaminedwhichbrainregionsmaybeinvolved.5.Arelationshipmayexistbetweenconcurrent(同时发生的)gutcolonizationandbraindevelopmentprocesses.第五页，共32页。Objectives第六页，共32页。1.Inthisprospective,longitudinalstudy,theresearcherstestedwhetherthe1-year-oldgutmicrobiomewasassociatedwithcognitiveoutcomesat1and2yearsofage.2.Theyhypothesizedthatinfantgutmicrobiomesampleswouldclusterintogroupsofcommunitysimilarityandthatcognitiveabilitywoulddifferbetweenclusters.根据群落相似性，肠道菌群样本可以聚类为不同的组，而聚类到不同组的婴儿可能具有不同的认知能力第七页，共32页。Methods第八页，共32页。1.StudyPopulationRecruited891-year-oldinfants(twinsandsingletons)fromtwoprospectivelongitudinalstudiesofearlybraindevelopmentattheUniversityofNorthCarolinaatChapelHill.两项关于早期大脑发育的前瞻性、纵向研究Exclusioncriteriafortheparentstudiesincludedfetalultrasoundabnormalitiesandmajormedicalillnessofthemother.第九页，共32页。2.MicrobiomeAnalysis（微生物群分析方法）Parentscollectedapproximately200mgoffecalmaterialfromasinglediaper,placeditinatubefilledwithAllprotectreagent（试剂）andreturneditthroughovernightshipping（连夜运送）.Oncereceived,sampleswerestoredat-80°Cuntilanalysis.MiSeqplatform（用于对细菌种类进行鉴别和量化）,QuantitativeInsightsIntoMicrobialEcologysoftware（用于获取生物学信息、多样性测定）,denovoalgorithm（用于最优分类单位选取）,ChimeraSlayer（用于嵌合测序）.Clusteringanalysiswascompletedwithdistancemetrics，Clusterscoringmethodswereusedtoassesstheoptimalnumberofclusters.第十页，共32页。3.GeneraAnalysisandCo-occurrenceNetworksTobetterunderstandtheuniquecommunitydynamicsofeachcluster,weusedonerepresentativegenerafromeachclusterasaseedtogenerateco-occurrencenetworksviaSpearmancorrelations.第十一页，共32页。4.CognitiveTestingTheMullenconsistsoffiveseparatescales,withtheirownage-groupstandardizednormativeTscoresandpercentiles,andanEarlyLearning(Cognitive)Composite(ELC).Thefivescalesmeasuregrossmotor,finemotor,visualreception,expressivelanguage,andreceptivelanguageskills.ThestandardizedTscoresoffourscales(grossmotornotincluded)arecombinedtocreatetheELC.Thisprovidedcognitivedatafor86subjectsat1yearofageand69subjectsat2yearsofage.第十二页，共32页。5.StructuralImageAcquisitionSiemenshead-only3TTIM-Trioscanner

Duringunsedatednaturalsleep婴儿在自然睡眠状态下的大脑成像Magnetizationpreparedrapidacquisitiongradient-echoscanswereobtainedatyears1and2Atotalof38infantsatyear1didnotgotosleeporwokeupinthescanner(successrate=57%).Atotalof61infantsatyear2didnotgotosleep,wokeupinthescanner,orwerelosttofollow-up(successrate=31%).

第十三页，共32页。6.ImageAnalysisBraintissuewasclassifiedasgraymatter,whitematter,andcerebrospinalfluid.ITK-SNAPsoftwareObtainedmeasuresofintracranialvolume,totalgraymatter,totalwhitematter,totalcerebrospinalfluid,lateralventriclevolume,and90-regiongraymattervolumesat1yearofagefor46subjectsandat2yearsofagefor27subjects.扫描结果提供了颅内容量、总灰质、总白质、总脑脊液、侧脑室体积和90区域灰质体积等信息第十四页，共32页。7.AssociationofCognitiveandBrainOutcomesWithClusterMembershipandAlphaDiversityLinearmixedeffectmodelswereusedtotestforeffectsof：1.cognitiveperformanceandbrainvolumes

2.clustermembershiponalphadiversityLikelihoodratiotestswereusedtotestthesignificanceofthecoefficientofeachclusterandalphadiversitymeasure.

Secondaryanalyseswereadjustedformultiplecomparisons第十五页，共32页。7.AssociationofCognitiveandBrainOutcomesWithClusterMembershipandAlphaDiversitySensitivityanalysesRawscoresTscoresDemographicandmedicalvariablesassociatedwithclustermembershiporalphadiversityandneuroimagingorcognitiveoutcomeswereincludedascovariates第十六页，共32页。8.MetagenomePredictionFromPhylogenetic

InvestigationofCommunitiesbyReconstruction

ofUnobservedStatesPICRUSt

（生物信息软件）wasusedtopredictmeta-genomefunctionalcontentfromthe16SribosomalRNAsequencingdata.第十七页，共32页。Results第十八页，共32页。1.InfantMicrobiotaClusterIntoThreeGroups

Cluster1(C1)characterizedbyarelativelyhighabundanceofFaecalibacterium;第一组的普氏菌属细菌丰度较高Cluster2(C2)byarelativelyhighabundanceofBacteroides;第二组的拟杆菌属细菌丰度较高Cluster3(C3)byarelativelyhighabundanceofanunnamedgenusinthefamilyRuminococcaceae.第三组以瘤胃球菌菌科一种未命名的细菌属的相对丰度较高为主要特征第十九页，共32页。第二十页，共32页。第二十一页，共32页。2.IdentificationofPredictorCovariates

C2组（拟杆菌丰度高）的婴儿在1岁时更少的是通过剖腹产出生、更多的是母乳喂养。第二十二页，共32页。2.IdentificationofPredictorCovariates

PaternalethnicityinC2was90%whitecomparedwithC3andC1.第二十三页，共32页。2.IdentificationofPredictorCovariates

InfantsinC2weremorelikelytobebreastfedat1yearofage.第二十四页，共32页。3.CognitiveAbilitiesDifferBetweenClusters第二十五页，共32页。4.AlphaDiversityCorrelatesWithCognitive

PerformanceFourmeasuresofalphadiversity,Chao1(CH1),observedspecies(OS),ShannonIndex(SI),andFaith’sPhylogeneticDiversity(FPD)weretestedforassociationswiththeELC.Alphadiversitymeasuresaccountedfor5%to23%ofthevarianceinMullenscores.FPD,SI,OS,andCH1wereallsignificantlydifferentbetweenclusters,withC1showingthegreatestalphadiversityandC2showingtheleast.第二十六页，共32页。在2岁时，肠道菌群α-多样性高与Mullen早期学习量表总得分以及视觉感知和语言表达评分较低有关。C1组的α-多样性最高，而C2组α-多样性最低。我们通常会认为肠道菌群多样性更高的婴儿可能会有更好的认知发育，因为多样性的肠道菌群通常会创造一个更稳定的功能群体，但是结果却是相反，为什么会这样？4.AlphaDiversityCorrelatesWithCognitive

Performance第二十七页，共32页。5.PredictedMetagenomeofGutMicrobiotaDiffers

BetweenClusters

C2showedthehighestperformanceontheMullenScales,andthereforewewereparticularlyinterestedinmetabolicdifferences

uniquetothisgroup；

C2hadincreased

genesinvolvedinmetabolismofbiotin,lipoicacid,folate,andubiquinoneandotherterpenoid；Genesinvolvedinbacterialchemotaxis,flagellarassembly,bacterialmotilityproteins,andcytoskeletonproteinsweredecreased.

C2组肠道微生物中，与叶酸、生物素代谢有关的基因增加了，而与细菌致病性（如细菌的趋化性、细菌的运动）相关的基因减少了；可能的解释是，多样化的菌群可能会含有一些对大脑发育具有潜在的负面影响的致病细菌，或者说在一个多样化的菌群中，所有的细菌必须共享资源，因此有益菌可利用的资源减少。第二十八页，共32页。Conclusion第二十九页，共32页。1.Microbialcompositionofthehumangutat1yearofagepredictscognitiveperformanceat2yearsofage,particularlyintheareaofcommunicativebehavior.2.Resultsmayhaveimplicationsfordevelopmentaldisorderscharacterize