Mucosal MicroRNAs Expression Profiles before and after Exclusive Enteral Nutrition Therapy in Adult Patients with Crohn's Disease.

MicroRNAs (miRNAs) have been shown to be important for the pathogenesis of Crohn's disease (CD). Exclusive enteral nutrition (EEN) is an effective therapy for inducing remission in CD. We aimed to investigate the alteration of miRNAs expression profile in the terminal ileal mucosa of CD patients before and after EEN. Twenty-five patients and ten healthy individuals were included. MiRNAs expression profile was firstly assessed using microarray technology and then validation was performed by qRT-PCR. The correlations between miRNAs and CD activity index (CDAI) score and serum C-reactive protein (CRP) level were also evaluated. Microarray analysis showed that mucosal miRNAs expression profile after EEN therapy was significantly changed compared with inflamed mucosa before treatment, and was most similar to the healthy one among all CD groups. Altered expressions of hsa-miR-192-5p, hsa-miR-423-3p, hsa-miR-99a-5p, hsa-miR-124-3p, hsa-miR-301a-5p, hsa-miR-495-5p, and hsa-let-7b-5p were confirmed by qRT-PCR. hsa-let-7b-5p was significantly correlated with serum CRP levels before and after EEN treatment (r = -0.518, p = 0.008, and r = -0.569, p = 0.003). Our study showed EEN induction therapy was associated with a trend for normalizing of the mucosal miRNAs expression profile, and expression of mucosal hsa-let-7b-5p was correlated with serum CRP level in patients with CD.