Identification of commercial microbes contributing to dysbiosis of Japanese patients with Crohn's disease.

(Background/aims) Dysbiosis is thought to be relevant to the etiology and pathogenesis of Crohn's disease (CD). In this study, we performed pyrosequence analysis of the gut microbiota of Japanese CD patients and identified bacteria species contributing to dysbiosis of CD patients.
(Materials and methods) Ten CD patients and 10 healthy controls were enrolled. Pyrosequence of 16s rRNA (430 bp of V3/V4 region) of fecal samples was performed using Miseq (Illumina, USA).
(Results) Cluster analysis showed that fecal bacterial communities of CD patients differed from those of healthy individuals. These changes are characterized by decreased abundance of Blautia faecis, Roseburia inulinivorans, Roseburia inulinivorans, Clostridium lavalense, Faecalibacterium prausnitzii, Christensenella minuta, and Eubacterium fissicatena. The majority of bacteria which contributed to formation of dysbiosis of CD patients were classified into the class of Clostridia.
(Conclusion) The decreased abundance of the class Clostridia may translate into a reduction of commensal bacteria-mediated anti-inflammatory activities in the mucosa, which are relevant to the pathophysiology of CD.