CancerCellReviewTheIntestinalMicrobiotainColorectalCancerHerbertTilg,1,3,*TimonE.Adolph,1,3RomanaR.Gerner,1,2,3andAlexanderR.Moschen1,2,31DepartmentofInternalMedicineI,Gastroenterology,Hepatology&Endocrinology,MedicalUniversityInnsbruck,Innsbruck,Austria2ChristianDopplerLaboratoryofMucosalImmunology,MedicalUniversityInnsbruck,Innsbruck,Austria3Theseauthorscontributedequally*Correspondence:herbert.tilg@i-med.ac.athttps://doi.org/10.1016/j.ccell.2018.03.004Experimentalevidencefromthepastyearshighlightsakeyrolefortheintestinalmicrobiotaininflammatoryandmalignantgastrointestinaldiseases.Dietexhibitsastrongimpactonmicrobialcompositionandpro-videsriskfordevelopingcolorectalcarcinoma(CRC).LargemetagenomicstudiesinhumanCRCassociatedmicrobiomesignatureswiththecolorectaladenoma-carcinomasequence,suggestingafundamentalroleoftheintestinalmicrobiotaintheevolutionofgastrointestinalmalignancy.Basicscienceestablishedacriticalfunctionfortheintestinalmicrobiotainpromotingtumorigenesis.Furtherstudiesareneededtodecipherthemechanismsoftumorpromotionandmicrobialco-evolutioninCRC,whichmaybeexploitedtherapeuticallyinthefuture.IntroductionTheimpactoftheintestinalmicrobiotaonhealthanddiseaseisincreasinglyemerging.Whilethemicrobiotaevolvedasa‘‘ne-glectedorgan’’intheearly2000s,ourperceptionin2018hasvastlychangedinthatthemicrobiotareflectsabiologicalecosystemthatintenselycommunicateswiththehost(Char-bonneauetal.,2016;LynchandPedersen,2016;Marchesietal.,2016;SonnenburgandBackhed,2016).Ahypeinmicro-biotaresearchinthelastdecadeallowedtodelineatethecompositionandsomefunctionsoftheintestinalmicrobiota,whichwasempoweredbytheintroductionofmodernmoleculartechniques.Currentestimatessuggestthatthegastrointestinaltractcontainsasmuchbacteriaascellscomposingthehumanbody(Senderetal.,2016).Althoughwecanadequatelydepicttheenormousdiversityofthehumanmicrobiota,theroleofmostbacterialspeciesinhealthanddiseaseremainslargelyun-known.Keyexamplesforaderangedinterplaybetweenthehostandthemicrobiotamaybederivedfr...
