Comparison of clinical effectiveness and microbiome impact between specific polymeric and monomeric diet for exclusive enteral nutrition in pediatric Crohn's disease: a prospective cohort study

Background: According to the ECCO-ESPGHN guideline for the treatment of newly diagnosed pediatric Crohn's disease (CD), exclusive enteral nutrition (EEN) treatment is recommended for inducing remission. This study aimed to compare the clinical effectiveness and changes in the microbiome between the monomeric diet and a specific polymeric diet. Methods: This prospective study included 38 healthy children and 48 pediatric patients with moderate to severe CD. The patients divided into two groups according to the type of EEN: monomeric diet (group A, n = 24) and polymeric diet (group B, n = 24). Results: All patients achieved clinical remission. Baseline alpha diversity was lower in CD patients than in healthy controls (p < 0.001). Shannon diversity was statistically associated with ESR (p = 0.037). Faecalibacterium, Streptococcus sanguinis group, Enterococcus had decreased after EEN treatment (p = 0.003, p = 0.003, p = 0.026, respectively). There were differences in bacterial taxa between the two groups before starting EEN, but these differences disappeared after EEN. Bacteroides acidifaciens group and Butyricicoccus faecihominis group were associated with CRP (p = 0.016, p = 0.027, respectively) and ESR (p = 0.004, p = 0.012, respectively). Conclusions: The polymeric diet, like the monomeric diet, can also induce clinical remission and is therefore a viable option for EEN treatment. An 8-week course of exclusive enteral nutrition is sufficient to achieve significant improvements in inflammation and weight gain. The microbiome was correlated with clinical indicators, but no significant differences were observed between the two groups.