CAG Postdoctoral – A2 CROHN DISEASE EXCLUSION DIET MAINTENANCE THERAPY INDUCES SUSTAINED MICROBIOME CHANGES

Abstract Background Crohn disease (CD) exclusion diet plus partial enteral nutrition (CDED+PEN) and exclusive enteral nutrition (EEN) are both effective at inducing remission in pediatric CD. Aims The aims of the current study were to characterize temporal microbiome alterations in children with CD receiving either CDED+PEN or EEN, and determine if microbiome restoration (more closely resembling healthy controls) was associated with sustained remission. We hypothesized that the diet therapies would induce distinct changes to the gut microbiome, and that this would be linked to improved clinical outcomes. Methods In a multi-centre randomized controlled trial, children (12.7±2.4 years) with mild-to-severe CD received EEN for 2 weeks followed by CDED+PEN (n=30) for up to 24 weeks, or 8 weeks of EEN followed by PEN with free diet (n=26). Fecal samples were collected at baseline and weeks 2, 8, 14, and 24 from patients, and at baseline from healthy family members (FM; n=108). Samples were subjected to 16S rRNA gene amplicon sequencing, and linear mixed models were applied; false discovery rate-adjusted p