P722 Intestinal microbiota in paediatric ulcerative colitis differs from healthy controls
E.F. de Groot*1, N.K. de Boer1, M.A. Benninga2, D.E. Budding3, A.A. van Bodegraven4, P.H. Savelkoul3, T.G. de Meij5
1VU University Medical Centre, Gastroenterology and Hepatology, Amsterdam, Netherlands, 2Academic Medical Center, Pediatric Gastroenterology and Hepatology, Amsterdam, Netherlands, 3VU University Medical Centre, Medical Microbiology and Infection control, Amsterdam, Netherlands, 4ORBIS Medical Centre, Gastroenterology and Hepatology, Sittard, Netherlands, 5VU University Medical Center, Pediatric Gastoenterology and Hepatology, Amsterdam, Netherlands
In the aetiology of ulcerative colitis (UC), intestinal microbiota is considered to play a crucial role, especially in adults. Knowledge on its role in children is limited. Here we studied intestinal microbiota in a cohort of children with newly diagnosed UC upon achieving remission.
Faecal samples were collected from patients suspected for UC, prior to bowel cleansing (t0) and at week 1, 3, 6 and 18 after initiation of therapy when diagnosis was confirmed. All patients were recruited from 2 tertiary centres in Amsterdam, The Netherlands. As control group, healthy children collected samples at similar time points. Disease activity was assessed by Global Physician Assessment (GPA) score, faecal calprotectin and CRP. Faecal samples were analysed by IS-pro, a clinically applicable PCR-based microbiome profiling technique.
Faecal samples of 41 newly diagnosed UC patients (median 13 years; IQR 5.6) and 60 healthy controls (median 8 years; IQR 3.3) were compared. All patients were treated according to standard care guidelines, comprising aminosalycilates for induction of remission, dependent on disease severity, combined with corticosteroids, and also as maintenance (mono)therapy. All patients were in clinical remission at t6. Preliminary results showed microbiota profiles of UC and controls were distinguishable. At t0, diversity and total abundance of the phylum Firmicutes were significantly higher in UC compared to controls (p0.003 and p0.001 respectively). Total abundance of Firmicutes in CU increased even further at t6 (p0.039). For the phylum Bacteroidetes total abundance was lower in UC compared to controls at t0 (p0.003). Furthermore one of the core microbiota in controls, Alistipes putredinis, was absent in almost all CU patients. Microbiota profiles in CU did not shift towards those of controls upon achieving remission.
Microbiota-analysis demonstrated significant differences in composition between paediatric UC and controls. One of the core microbiota in controls, Alistipes putredinis, had a lower abundance or was totally absent in almost all UC patients. Upon achieving remission, overall microbiota composition of UC patients did not change towards that of healthy control.