An Open Label Non Randomized Pilot Study: Use of the Ulcerative Colitis Diet for Induction of Remission.

Background:

Recent research has shown that dietary components may lead to impaired intestinal innate immunity due to alterations in the microbiome, mucous layer, intestinal permeability or change in bacterial adherence and translocation. Pfeffer Gik et al (Dig Dis, 2014) compiled a list of food components and additives that impair the intestinal epitheliums ability to contain bacteria to the lumen, and consequently increase intestinal permeability which, in turn, increases the uptake of luminal antigens and microbial factors. The list includes Gliadin, Saturated fat milks, emulsifiers such as Carboxymethylcellulose, Polysorbate 80 and Sodium Caprate )Levine A, Wine E, 2013). In Crohn's disease, intervention with EEN or a Crohn's disease exclusion diet have shown high rates of remission in mild- moderate CD patients. The CDED led to remission in 70% of patients, primarily with patients with early mild to moderate disease (Sigall-Boneh R et al, 2014).

Unlike CD, none of these studies have systematically examined the relationship between normal diet intake and relapses in UC. Devotka et al demonstrated that a bloom in sulphide reducing bacteria increased colitis in IL10-/- mice. This was due to increased Bilophila Wadsworthia which is sulphide dependent (Brown k et al, 2012). Studies have shown that the rate of butyrate utilization in normal specimens was almost double than that found in UC Specimens. Moreover, high fiber diet can affect the microbial composition (Pitcher MCL et al, Gut, 2000) and regulatory T cells in the colon (Singh N et al, 2014).

Until recently, UC was not considered to be a bacteria mediated disease. However, our increased understanding of UC indicates that bacteria might have a role in pathogenesis or severity of the disease. The strongest evidence comes from Japanese studies in patients with moderate to severe colitis, which demonstrated that triple therapy with penicillin , tetracycline and metronidazole led to remission in steroid refractory patients in 60% of patients, and this was reproduced in a follow up randomized controlled trial which showed a 70% remission rate (UEGW Amsterdam 2012, Ohkusa T et al 2005 ). On the other hand a previous trial had shown 44% response and only (Ohkusa T et al 2010). A recent retrospective study in Israel showed a 65% response and 50% remission rate in patients with severe refractory colitis. Thus it is unclear at present if antibiotics are useful only in severe colitis , or if this reflects heterogeneity among studies.

Diet and antibiotics are the two proven treatments that may alter the microbiota clinically. Theoretically, controlling the microbiota by diet or antibiotics may allow for control of the disease without immune suppression , and this has yet to be evaluated.