Lack of efficacy of a reduced microparticle diet in a multi-centred trial of patients with active Crohnʼs disease

BACKGROUND AND AIMSDietary microparticles, which are bacteria-sized and non-biological, found in the modern Western diet, have been implicated in both the aetiology and pathogenesis of Crohnʼs disease. Following on from the findings of a previous pilot study, we aimed to confirm whether a reduction in the amount of dietary microparticles facilitates induction of remission in patients with active Crohnʼs disease, in a single-blind, randomized, multi-centre, placebo controlled trial. METHODSEighty-three patients with active Crohnʼs disease were randomly allocated in a 2×2 factorial design to a diet low or normal in microparticles and/or calcium for 16 weeks. All patients received a reducing dose of prednisolone for 6 weeks. Outcome measures were Crohnʼs disease activity index, Van Hees index, quality of life and a series of objective measures of inflammation including erythrocyte sedimentation rate, C-reactive protein, intestinal permeability and faecal calprotectin. After 16 weeks patients returned to their normal diet and were followed up for a further 36 weeks. RESULTSDietary manipulation provided no added effect to corticosteroid treatment on any of the outcome measures during the dietary trial (16 weeks) or follow-up (to 1 year); e.g., for logistic regression of Crohnʼs disease activity index based rates of remission (P=0.1) and clinical response (P=0.8), in normal versus low microparticle groups. CONCLUSIONSOur adequately powered and carefully controlled dietary trial found no evidence that reducing microparticle intake aids remission in active Crohnʼs disease.