P710 Microbiota dynamics in paediatric Crohn's disease from active disease upon achieving clinical remission
T. de Meij*1, E. de Groot2, M. Benninga3, D. Budding4, N. de Boer2, A. van Bodegraven2, P. Savelkoul5
1VU university medical center, paediatric gastroenterology, amsterdam, Netherlands, 2VU University Medical Centre, Gastroenterology and Hepatology, Amsterdam, Netherlands, 3Academic medical centre , paediatric gastroenterology, amsterdam, Netherlands, 4VU university medical center, Medical Microbiology and infection control, Amsterdam, Netherlands, 5VU University Medical Centre, Medical Microbiology and Infection control, Amsterdam, Netherlands
In Crohn's disease (CD), genetic and environmental factors like alterations in intestinal microbiota composition, are considered to play a crucial etiological role. However, data on paediatric cases is limited and conflicting. Here we aimed to describe the intestinal microbiota composition in a cohort of children with newly diagnosed CD, from active disease up to three months following initiation of therapy.
Faecal samples were collected from children aged up to 18 years and suspected for CD, prior to bowel cleansing (baseline) and at week 1, 3, 6 and 18 following initiation of therapy. All patients were treated according to standard care guidelines. CD-patients were offered 6 weeks exclusive enteral nutrition (EEN) and in case of EEN-reluctance, failure or intolerance, corticosteroids were prescribed. As maintenance therapy thiopurines were prescribed. Disease activity was assessed by Global Physician Assessment (GPA) score, substantiated by fecal calprotectin and CRP. As control group, healthy children were invited to collect faecal samples at similar time-intervals as the study-group. Faecal samples were analysed by IS-pro (interspace 16-23S, PCR-based microbiome detection technique.
Faecal microbiota profiles of 60 children with newly diagnosed CD (median 14 years; IQR 2.6) over time were compared to 60 healthy controls (median 8 years; IQR 3.3). 95% of CD patients were in clinical remission at t6. At baseline, Shannon diversity index in CD cases was higher for the phylum Proteobacteria, compared to controls (p0.041), next to a higher total abundance (p0.001). At baseline, total abundance of phylum Bacteroidetes was lower in CD compared to controls (p0.07). Upon achieving clinical remission, microbiota profiles seemed to resemble profiles healthy controls. Notably, microbiota profiles of CD patients, from baseline to 6 weeks follow-up, showed shifts towards composition of healthy controls.
Significant differences in intestinal microbiota were observed in a large cohort of paediatric CD patients and controls, mainly within phylum Proteobacteria, both in stability and diversity. From active disease upon achieving clinical remission, microbiota profiles of CD subjects showed microbial shifts towards healthy state. Observed microbiota alterations in CD, from active disease upon achieving clinical remission, could lead to development of novel, personalized, microbiota-targeted strategies.