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: The therapeutic role of enteral nutrition and diet in patients with ulcerative colitis (UC) has not been adequately explored. We aimed to evaluate the effectiveness of partial enteral nutrition (PEN) in combination with an 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. The primary outcome was clinical remission (SCCAI ≤2) at week 4. In addition, fecal microbiota analysis was performed at baseline and at week 4 for 14 participants in the PEN+ED group. Results: Sixty patients were included (PEN+ED = 30; SOC = 30). Baseline disease activity parameters were similar between the two groups. At week 4, 66.7% (20/30) of patients in the PEN+ED arm achieved clinical remission compared to 83.3% (25/30) receiving SOC. The proportion of patients with rectal bleeding score "0" was significantly lower in PEN+ED (56.7% vs 86.7%, 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. Clinical trial registration number: ISRCTN15559229.