Exclusive enteral nutrition remodels the intestinal flora in patients with active Crohn's disease

Background: Although there are many hypotheses, the pathogenesis of Crohn's disease (CD) is not completely clear so far. Exclusive enteral nutrition (EEN) is a routine measure in the treatment of active CD. We aimed at investigating the impact of EEN on patients with active CD from microbial metabolomics. Methods: 16S-rDNA sequencing technology and gas chromatography-mass spectrometer analysis were employed to investigate the modification of the intestinal flora and fecal short-chain fatty acid (SCFA) during the EEN. Results: Seven patients with CD, who conducted EEN, were followed up successfully in the present study. The 8-week EEN resulted in a remission of the condition of subjects with active CD, as revealed by a significant decrease in erythrocyte sedimentation rate (ESR) (P = 0.018), C-reactive protein (CRP) (P = 0.028), and Crohn's disease activity index (CDAI) (P= 0.018). The nutrition of the subjects was improved after an 8-week treatment course with EEN, which was associated with an increase in body mess index (BMI) (P = 0.018) and serum albumin (ALB) (P = 0.018) levels. Furthermore, our investigations revealed a significantly increased abundance of Firmicutes paralleled by decreased levels of Proteobacteria. With respect to the genus, five species of bacteria including Ruminococcus (P = 0.01), Lachnospiraceae (P = 0.02), Anaerotruncus (P = 0.04), Flavonifractor (P = 0.04), and Novosphingobium (P = 0.05) showed significantly increased abundance. This was accompanied by relative changes in fecal short-chain fatty acids levels. Moreover, we successfully constructed a stable model by combining these five significantly different genera to predict the therapeutic effect of EEN on patients with CD (AUC= 0.9598). Conclusions: The findings indicated that EEN can alleviate the condition and the nutrition of patients with active CD by regulating the intestinal flora and influencing the expression level of fecal short-chain fatty acids.