Exploring Different Effects of Exclusive Enteral Nutrition (EEN) and Corticosteroids on the Gut Microbiome in Crohn's Disease Based on a Three-Stage Strategy

The objective of this study was to compare the efficacy of exclusive enteral nutrition (EEN) and corticosteroids on the gut microbiome in Crohn's disease. Methods. Data were collected for 16 patients newly diagnosed with CD as the test group and 10 healthy volunteers as the control group. The 16 patients were randomly divided into the EEN group and the corticosteroids group. For subsequent analysis, 6 patients in the EEN group with follow-up were enrolled to compare the 0-month, 1-month, and 3-month outcomes. We analyzed and compared gut microbiota between different groups in 3 stages. To evaluate the clinical outcome of treatment, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), hemoglobin (HB), albumin (ALB), and Crohn's disease activity (CDAI) were recorded. Results. There are significant differences in microbiota between patients with CD and healthy people, and there are intuitive differences in the main components of the microbiota. 16 patients were included in stage 2, in which both corticosteroids and EEN can induce CD remission well. However, corticosteroids have a greater impact on inflammatory indicators, while EEN has a more obvious effect on nutritional indicators. Principal component analysis suggests that there are different compositional changes in the gut microbiome after corticosteroids and EEN treatment. After 3 months of dynamic observation, we found that EEN can effectively maintain CD remission, reduce inflammatory indicators, and improve nutritional indicators. Conclusions. Both EEN and corticosteroids can increase the diversity of the microbiome in inducing CD remission, while they have different effects on the proportion of microbiome species. This trial is registered with NCT02056418.