Effect of Fat Composition in Enteral Nutrition for Crohn's Disease in Adults: A Systematic Review

Background & Aims: The role of enteral nutrition (EN) fat composition in regulating inflammation in Crohn's disease (CD) is not clear. There is, moreover, insufficient evidence to guide the choice of EN in CD with any confidence. We have reanalysed the findings of previous studies in a systematic review focussing on the relationship between EN fat content and remission rates (RR).

Methods: A systematic search with no language restriction was undertaken in Medline and Embase databases supplemented by a manual search in the reference lists of identified studies. The selection criteria were: clinical trial, exclusive EN, adults and CD. Data on the type of EN, its fat composition, achieved RR, and study design were extracted. An established assessment tool was used to assess the quality of the studies.

Results: A total of 29 clinical trials are included in this review. The quality of the studies was highly variable. No fewer than 27 formulations of enteral feed were identified including 4 elemental and 23 non-elemental preparations. There was a positive correlation between the total n-6 fatty acid content and response rates, which was significant when expressed as the ratio between n-6 and n-3 fatty acids (r = 0.378, p = 0.018). A non-significant positive trend was founded (r = 0.072; p = 0.643) between medium chain triglycerides (MCT) delivery as a percentage of the total energy provision and RR. While a non-significant negative trend was reported for the delivery of monounsaturated fatty acids (MUFA) (r = -0.23, p = 0.13). A qualitative advantage to regimens based on safflower oil suggest that optimised therapeutic approaches are within reach.