Background and aims: Clinical and experimental data suggest that gut microbiota plays an important role in the pathogenesis of inflammatory bowel disease (IBD). The aim of this study was to determine intestinal microbiota in newly diagnosed patients with IBD and to compare it with patients' healthy siblings who share same genetic and environmental background and to healthy unrelated controls.
Methods: Molecular approach targeting 16S ribosomal RNA was employed for analyzing the gut microbiota of participants' stool samples. Terminal restriction fragment length polymorphphism analysis was performed.
Results: Newly diagnosed pediatric patients with IBD (n = 19, 68.4% Crohn disease [CD], mean age 14.8 ± 0.65 years), their unaffected healthy siblings (n = 20, mean age 12.8 ± 0.85 years), and unrelated healthy controls (n = 19, mean age 10.7 ± 0.8 years) were included. Microbial diversity differed significantly between IBD patients, healthy siblings, and healthy controls (P = 0.018 for MspI digestion, P = 0.013 for HhaI digestion). No significant difference in microbial diversity was found between healthy siblings and healthy controls. In patients reduced presence of genus Eubacterium, Lactobacillus, Enterobacter and Clostridium, and increased presence of genus Streptococcus, Prevotella and Escherichia, compared with healthy siblings and healthy controls, was found.
Conclusion: Newly diagnosed pediatric patients with IBD show significantly less diverse microbiota and microbial composition compared with healthy siblings and healthy controls.