Impacts of long-term enteral nutrition on clinical and endoscopic disease activities and mucosal cytokines during remission in patients with Crohn's disease: A prospective study

Background: Long-term enteral nutrition may maintain clinical and endoscopic remission in patients with Crohn's disease (CD). The aim of this prospective study was to investigate the impacts of long-term enteral nutrition on clinical and endoscopic disease activities and mucosal tissue cytokines in patients with quiescent CD. Methods: Forty patients with CD who achieved clinical remission were included. Of these, 20 received continuous elemental diet (Elental) infusion during the nighttime and a low-fat diet during the daytime (EN group) and 20 received neither nutritional therapy nor food restriction (non-EN group). With these regimens, all 40 patients were monitored for 1 year. Further, ileocolonoscopy was performed at entry, at 6 and 12 months, and mucosal biopsies were taken for cytokine assays. Results: On an intention-to-treat basis, 5 patients (25%) in the EN group and 13 (65%) in the non-EN group had a clinical relapse during the I-year observation (P = 0.03). The mean endoscopic inflammation (EI) scores were not significantly different between the groups at both entry and 6 months, but at 12 months El scores were significantly higher in the non-EN group than in the EN group (P = 0.04). Additionally, the mucosal tissue interleukin (IL)-1 beta, IL-6, and tumor necrosis factor (TNF)-alpha levels significantly increased with time in the non-EN group (entry versus 12 months, IL-1 beta, P = 0.02; IL-6, P = 0.002; TNF-alpha, P = 0.001). In the EN group these cytokines did not show a significant increase. Conclusions: Long-term enteral nutrition in patients with quiescent CD has a clear suppressive effect on clinical and endoscopic disease activities and the mucosal inflammatory cytokine levels.