P125 Could gut microbiota metagenomic analysis improve diagnosis in paediatric Inflammatory Bowel Disease population?

Pujol Muncunill, G.(1);Monleon-Getino, A.(2);Méndez-Viera, J.(2);Álvarez-Carnero, L.(1);Martin de Carpi, J.(1);

(1)Hospital Sant Joan de Déu, Unit for the Comprehensive Care of Pediatric Inflammatory Bowel Disease. Department of Pediatric Gastroenterology- Hepatology and Nutrition, Esplugues de Llobregat, Spain;(2)Faculty of Biology- Universitat de Barcelona., Genetic- microbiology and statistics Department., Bacelona, Spain


Gut microbiota plays an important role in maintaining intestinal homeostasis. Recent studies postulate that dysbiosis may be involved in the pathogenesis of Inflammatory Bowel Disease (IBD). The aim of the study was to characterize the metagenomic biodiversity of the gut microbiota in Paediatric Inflammatory Bowel Disease patients (PIBD) and whether microbiome data could be used as diagnostic tool.


A prospective, longitudinal observational pilot clinical trial with consecutive inclusion of PIBD patients matched with healthy controls by age and sex was performed. A total of 36 children were planned to be included: 12 Crohn's Disease (CD), 12 Ulcerative Colitis (UC) and 12 healthy controls (HC). Demographic, clinical and analytical data were recorded and stool and saliva samples were collected at onset, 3 and 6 months for DNA sequencing and bioinformatics analysis.


Twenty-three patients (12CD, 11UC) and 9 HC were included (at the time of data analysis). Fifty-six percent were male; mean age: 11.7 years (IQR: 8-15). CD patients at onset had a mean Paediatric Crohn's Disease Activity Index (PCDAI) of 22.5 (IQR: 10-55), a mean Faecal Calprotectin (FC) of 2384 mg/kg (IQR: 159-6000) and 83% of them had inflammatory markers elevation (Erythrocyte Sedimentation Rate (ESR) and/or C-reactive protein (CRP)). Patients with UC presented a mean Paediatric Ulcerative Colitis Activity Index (PUCAI) of 43.6 (IQR: 10-80) at onset, mean CF of 3381 mg/kg and 18% presented an increase of inflammatory markers (ESR and/or CRP). To date, Next Generation Sequencing (NGS) metagenomic study (saliva and stools) has been performed from 15 subjects (9 CD, 2 UC and 4 HC) at onset and 9 subjects (7 CD and 2 UC) at 3 months. A differential microbiota pattern was observed in both, saliva and stools, for CD at onset and at 3 months. In the stools, three differential taxa were found at onset of the disease and at 3 months and in saliva, another three differential taxa were observed compared to HC. In UC, 6 differential taxa (> 3 % diff. HC-UC, p-value=0) were selected in stools and 7 in saliva at onset compared to HC. Globally, a higher microbial biodiversity was observed for HC compared to CD at onset, but it was not statistically significant.


Provisional results showed a possible differential signature in both saliva and stools of patients with paediatric CD. These results must be validated with all the samples in process, and probably using larger paediatric cohorts before the development of these techniques as a diagnostic tool in the clinical practice.