Intestinal dysbiosis in pediatric Crohn's disease patients with mutations.

Background: Several studies have employed animal models to explore the association between microbiota and interleukin (IL) 10 signaling; however, limited information is available about the human microbiome.

Aim: To characterize the microbiome in patients with mutations and to explore the association between gut dysbiosis and disease severity.

Methods: Fecal samples were collected from patients who were diagnosed with loss-of-function mutations in the gene between January 2017 and July 2018 at the Children's Hospital of Fudan University. Age-matched volunteer children were recruited as healthy controls. Patients with Crohn's disease (CD) were used as disease controls to standardize the antibiotic exposure. Microbial DNA was extracted from the fecal samples. All analyses were based on the 16S rRNA gene sequencing data.

Results: Seventeen patients with mutations (IL10RA group), 17 patients with pediatric CD, and 26 healthy children were included. Both patients with mutations and those with CD exhibited a reduced diversity of gut microbiome with increased variability. The relative abundance of was substantially increased in the IL10RA group ( 0.02). On further comparison of the relative abundance of taxa between patients with mutations and healthy children, 13 taxa showed significant differences. The IL10RA-specific dysbiosis indices exhibited a significant positive correlation with weighted pediatric CD activity index and simple endoscopic score for CD.

Conclusion: In patients with mutations and early onset inflammatory bowel disease, gut dysbiosis shows a moderate association with disease severity.