Colonic mucosa-associated microbiota analysis in newly diagnosed Lithuanian paediatric IBD cases

Background: Changed intestinal microbiota leads to the imbalance of anti- and pro-inflammatory response and the development of chronic inflammation. The aim of the study was to investigate the characteristics of the gut microbiota in paediatric inflammatory bowel disease (IBD). Methods: Sigmoid mucosal biopsies sampled from seven paediatric patients with newly presenting, untreated, active IBD (3 Crohn’s disease (CD) and 4 ulcerative colitis (UC)), and 9 healthy controls were analysed using 16S rRNA gene profiling (V1-V2 region) at both DNA and RNA levels. Results: Standing and active community structure differences were determined according to gender, health or age conditions. The active members of the Firmicutes and Bacteroidetes showed significant differences between gender and health conditions. The standing and active microbial community members of Actinobacteria showed a consistent increase with age and decrease with disease. Alpha-diversity analysis revealed significant differences between active bacteria community and pathology. There was observed increase of closely related species in the state of UC compared with CD. Analysis of β diversity did not reveal any significant differences between operational taxonomic unit distribution and gender, health condition or their interaction. Conclusions: In paediatric IBD patients the structure differences of standing and active intestinal microbiota were associated with age, gender and health status. Diversity differences of clos [...]