Taxonomic abundance comparison between children with IBS and healthy children. The pediatric gut microbiomes of children with IBS are characterized by greater abundance of Pasteurellales. Taxonomic classification was made using RDP classifier (Order) with 454 sequencing data. A) Percentage of all bacterial Orders represented. B) Percentage of bacterial taxa found in lower abundance (< 8% of total bacteria). Healthy children include 29 samples from 22 subjects, IBS patients include 42 samples from 22 patients (V1-V3 region). #: Significantly different between IBS and healthy children (P <.05).