Dysbiosis of the fecal microbiota in the TNBS-induced Crohn's disease mouse model.

Crohn's disease (CD) is characterized by chronic transmural inflammation. The symptom of the mice model induced by 2,4,6-trinitrobenzenesulfonic acid (TNBS) is closed to human under CD condition, so this kind of animal is widely used in the related researches. Although the dysbiosis of the fecal microbiota has been proved to play an important role in the patients with CD, the composition of the gastrointestinal microbiota in the mouse model under disease condition is still unclear. In the current study, male 7-week BALB/c mice were anesthetized and intrarectal administrated by ethanol (ET group), TNBS in ethanol (TN group), and phosphate buffered saline (PBS) (CK group) as control. The symptoms of individuals under the CD condition were observed, and the changes of the bacterial taxonomic structure and functional composition were revealed by next-generation sequencing (NGS) 16S sequencing. The BALB/c mice in TN group demonstrated CD-like symptoms and the damages in the intestinal tract. The NGS 16S results exhibited that the diversity and microbial composition under CD condition are significantly different with those in ET group. The KEGG Orthology (KO) profile were generated from PICRUSt, and function modules such as methanogenesis (M00347) and microcin C transport system (M00349) were found enriched in the individuals in the TN group. This study proved that mouse model induced by TNBS could develop the similar symptom to CD patient, and we firstly showed the significant intestinal microbe changes on both taxonomic structure and functional composition in this mouse model.