Exclusive enteral nutrition in Crohn's disease: Evidence and practicalities

Abstract

Exclusive enteral nutrition (EEN) is the first line therapy for paediatric Crohn's disease, providing a complete nutritional feed whilst simultaneously inducing remission in up to 80% of cases. The effect of EEN on systemic/local intestinal immune function and subsequent inflammation (including barrier permeability, direct anti-inflammatory effects and cytokine signalling pathways), alongside changes in the microbiome (specific species and broad taxonomic shifts, functional changes) are becoming clearer, however the exact mechanism for induction of remission in Crohn's disease remains uncertain. The evidence of efficacy in paediatric Crohn's disease is strong, with selected adult populations also benefiting from EEN. However despite recommendations from all major societies (ECCO, ESPGHAN, NASPGHAN and ESPEN) first-line use of EEN is varied and Europe/Australasia/Canada show significantly more routine use than other parts of North America. Growth and nutritional status are significantly improved with EEN compared to corticosteroids but long-term outcomes are sparse. This review discusses the evidence underlying the use of EEN, highlighting the mechanisms thought to underlie how EEN induces remission in Crohn's disease, when and how to use EEN, including practical issues in both paediatric and adult practice (formulation, compliance, volumes and administration), and summarises the ongoing research priorities.

Exclusive enteral nutrition: An optimal care pathway for use in adult patients with active Crohn's disease

“…Gradual upgrade of formula over a 2–7‐day period may be required if an elemental formula is used as these are less palatable and can be poorly tolerated. Titration of therapy may also be required in those with problematic vomiting or diarrhea or are at risk of refeeding syndrome …”

“…A normal, unrestricted diet in line with national healthy eating guidelines should be the final goal of therapy when food is reintroduced . Limited data propose three dietary options for food reintroduction: an unrestricted diet, an exclusion/elimination diet, and a low‐fat/fiber exclusion diet; however, it is unclear whether particular dietary components actually influence the success of food reintroduction after EEN therapy …”

“…The basic premise of efficacy is the same as pediatric patients, yet few studies have been conducted on the adult cohort. This difference has been attributed to the lack of access to a multidisciplinary team, perceived intolerance and noncompliance in adults, and a lack of experience amongst inflammatory bowel disease (IBD) physicians . Subsequently, clinical guidelines for using EEN therapy in adults with active CD have not been developed.…”

“…Although high‐quality studies are limited, and existing study findings are heterogeneous, EEN may offer similar efficacy to corticosteroids for induction of remission in adults with CD . EEN has advantages over corticosteroids not only via avoidance of steroid‐related side effects but through improvement in nutritional indices, endoscopic mucosal healing, and treatment of IBD‐related complications such as strictures and fistulae, leading to surgical avoidance …”

Inducing remission in paediatric Crohn’s disease using nutritional therapies – A systematic review

“…A recent study by Ashton et al . provides a good review of the evidence surrounding these proposed mechanisms and some of the theories are discussed below in the context of the objectives and findings of the present systematic review.…”