Analysis of Gut Microbiome and Diet Modification in Patients with Crohn's Disease

Objective: Thehumanintestineharborstrillionsofcommensal � microbesthatliveinhomeostasiswiththehostimmunesystem. � Changesinthecompositionandcomplexityofgutmicrobial � communitiesareseenininflammatoryboweldisease �(IBD), �indicating � disruptioninhost-microbeinteractions. �Multiplefactorsincluding � dietandinflammatoryconditionsalterthemicrobialcomplexity. �The � goalofthisstudywastodevelopanoptimizedmethodologyforfecal � sampleprocessingandtodetectchangesinthegutmicrobiotaof � patientswithCrohn'sdiseasereceivingspecializeddiets.� Design:�Fe calsampleswereobtainedfrompatientswithCrohn's � diseaseinapilotdietcrossovertrialcomparingtheeffectsofa � specificcarbohydra tediet �(SCD) �versusalowresiduediet �(LRD) �on � thecompositionandcomplexityofthegutmicrobiotaandresolution � ofIBDsymptoms. � Thegutmicrobiotacompositionwasassessed � usingahigh-densityDNAmicroarrayPhyloChip.� Results:� DNAextractionfromfecalsamplesusingacolumn � basedmethodprovidedconsistentresults. �Thecomplexityofthegut � microbiomewaslowerinIBDpatientscomparedtohealthycontrols. � AnincreasedabundanceofBacteroides fragilis (B. fragilis)� was � observedinfecalsamplesfromIBDpositivepatients. �Thetemporal � responseofgutmicrobiometotheSCDresultedinanincreased � microbialdiversitywhiletheLRDdietwasassociatedwithreduced � diversityofthemicrobialcommunities.�