Background:
Predicting response to exclusive enteral nutrition (EEN) in active Crohn’s disease (CD) could lead to therapy personalization and pretreatment optimization.

Objectives:
This study aimed to explore the ability of pretreatment parameters to predict fecal calprotectin (FCal) levels at EEN completion in a prospective study in children with CD.

Methods:
In children with active CD, clinical parameters, dietary intake, cytokines, inflammation-related blood proteomics, and diet-related metabolites, metabolomics and microbiota in feces, were measured before initiation of 8 wk of EEN. Prediction of FCal levels at EEN completion was performed using machine learning. Data are presented with medians (IQR).

Results:
Of 37 patients recruited, 15 responded (FCal < 250 μg/g) to EEN (responders) and 22 did not (nonresponders). Clinical and immunological parameters were not associated with response to EEN. Responders had lesser (μmol/g) butyrate [responders: 13.2 (8.63–18.4) compared with nonresponders: 22.3 (12.0–32.0); P = 0.03], acetate [responders: 49.9 (46.4–68.4) compared with nonresponders: 70.4 (57.0–95.5); P = 0.027], phenylacetate [responders: 0.175 (0.013–0.611) compared with nonresponders: 0.943 (0.438–1.35); P = 0.021], and a higher microbiota richness [315 (269–347) compared with nonresponders: 243 (205–297); P = 0.015] in feces than nonresponders. Responders consumed (portions/1000 kcal/d) more confectionery products [responders: 0.55 (0.38–0.72) compared with nonresponders: 0.19 (0.01–0.38); P = 0.045]. A multicomponent model using fecal parameters, dietary data, and clinical and immunological parameters predicted response to EEN with 78% accuracy (sensitivity: 80%; specificity: 77%; positive predictive value: 71%; negative predictive value: 85%). Higher taxon abundance from Ruminococcaceae, Lachnospiraceae, and Bacteroides and phenylacetate, butyrate, and acetate were the most influential variables in predicting lack of response to EEN.

Conclusions:
We identify microbial signals and diet-related metabolites in feces, which could comprise targets for pretreatment optimization and personalized nutritional therapy in pediatric CD.