P1004 The Effects of a Dual-Strain Probiotic Versus Placebo on the Microbiome in Patients with Ulcerative Colitis
Authors: Carroll A , Walker C , Magdeldin H , Ryan B , O’Donnell S , McNamara D , Breslin N , Corr S , O’Connor A 
Published: January 2025

Abstract

Background
Ulcerative colitis (UC) is a form of Inflammatory Bowel Disease (IBD) characterised by chronic mucosal inflammation of the colon. It has been shown that fatigue in patients with ulcerative colitis is a particularly burdensome symptom[1]. Studies have shown that patients with IBD have higher fatigue scores than non-IBD control groups[1]. In UC, alterations in the microbiome is understood to be a contributing factor to the pathophysiology of the disease and have been found to be reduced compared with healthy controls[2-4]. The aim of this study therefore is to evaluate the effects of a dual-strain probiotic versus placebo and assess its effects on the microbiome.

Methods
This is a single centre double-blind randomised placebo-controlled trial in Tallaght University Hospital, Dublin. Participants are between the ages of 18 to 65 and have a confirmed diagnosis of ulcerative colitis. After randomisation, participants were enrolled on either a 3 month probiotic or placebo arm. Participants had blood tests and a faecal calprotectin at baseline and at conclusion of the study. The probiotic is a dual strain Bifidobacterium longum 35624® combined with B. longum 1714®.

Results
10 controls and 59 participants meeting eligibility criteria were successfully recruited. After double-blind randomisation, 30 participants were on the active dual-probiotic arm with 29 participants on the placebo arm (table 1). In our microbiome analysis the taxonomic composition was as expected of a faecal microbiome, with high abundances of Faecalibacterium, Bacteroides, and Phocaeicola. The measured alpha diversity, the measure of the diversity, richness and relative abundance of taxa within a sample, were within expected ranges across the probiotic and placebo group and across timelines. Shannon alpha diversity was significantly higher in the placebo treatment group, both when considering both baseline analysis and post-intervention analysis and when considering only the post-intervention timepoint (table 2).

Conclusion
This was an exploratory endpoint and further studies need to be done with non-UC healthy controls to further elucidate any clinically significant changes on the diversity of the microbiome when exposed to probiotics. Targeted probiotics with strains of specific taxa based on individual microbiome profiling may be more beneficial than generic probiotics in UC.

References
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