Partial enteral nutrition combined with an exclusion diet promotes a healthy gut microbiome in patients with mild to moderately active ulcerative colitis: A quasi-experimental study

Background and Aims Therapeutic role of enteral nutrition and diet in patients with ulcerative colitis (UC) has not been adequately explored. We aimed to evaluate effectiveness of partial enteral nutrition (PEN) in combination with exclusion diet (ED) in patients with UC. Methods In this prospective, open label, non-randomized, quasi-experimental study, patients with mild-to-moderate UC (simple clinical colitis activity index [SCCAI]3-9) were non-randomly allocated to either PEN+ED along with standard of care (SOC) or SOC alone for 4 weeks. Primary outcome was clinical remission (SCCAI ≤ 2) at week4. In addition, fecal microbiota analysis was performed at baseline and at week 4 for 14 participants in PEN+ED group. Results Sixty patients were included (PEN+ED = 30; SOC = 30). Baseline disease activity parameters were similar between both groups. At week 4, 66.7%(20/30) patients in the PEN+ED arm achieved clinical remission compared to 83.3%(25/30) receiving SOC. Proportion of patients with rectal bleeding score ‘0’ was significantly lower in PEN+ED (56.7%vs86.7%, p = 0.01) arm at week 4. A numerically higher number of patients required steroids in SOC arm compared to PEN+ED arm, but it was not significant (23.3%vs16.7%, p = 0.748). Microbiome analysis significant improvements in alpha diversity, increased relative abundance of beneficial gut microbes, depletion of pathobionts and shift towards a healthier microbial profile, which was in turn shown to be negatively associated with disease severity. Conclusions Although PEN+ED does not appear to have additional clinical benefit to SOC at week 4, it was associated with significant improvement in gut microbiota. Long-term benefits of dietary interventions should be explored in future studies.