Ethnicity Associated Microbial and Metabonomic Profiling in Newly Diagnosed Ulcerative Colitis

Gut microbiome predictors of advanced therapy response in Crohn's disease: protocol for the OPTIMIST prospective, longitudinal, observational pilot study in Canada

INTRODUCTION

Inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis, is characterised by chronic and relapsing inflammation of the gastrointestinal tract, leading to significant morbidity and reduced quality of life. The global rise in IBD incidence is driven by a complex interplay of genetic, environmental, dietary and microbiome-related factors. Despite advancements in treatment, such as biologics, response rates remain variable, highlighting the need for personalised approaches. Recent research suggests that specific microbiome signatures may serve as biomarkers for predicting therapeutic efficacy, offering a potential tool for optimising treatment strategies in CD. The aim of the Optimising IBD Patient Treatment with Integrated Microbiome Investigation for Specialised Therapeutics (OPTIMIST) study is to evaluate microbiome profiles across various sample types in a Canadian CD cohort starting or already on advanced therapy, with the goal of developing predictive models for personalised therapeutics.

METHODS AND ANALYSIS

This study is a two-phase, longitudinal, prospective observational pilot study conducted in British Columbia, Canada, involving both CD patients and non-IBD controls. Phase 1 focuses on baseline microbiome differences across participant cohorts through cross-sectional analysis. Phase 2 follows participants over 12 months to assess microbiome changes and their association with treatment response. Stool samples, intestinal biopsies from the left colon, right colon and ileum, as well as mucosal wash samples from the proximal part of the distal colon, will undergo metagenomics, metaproteomics and metabolomics analyses to explore compositional and functional differences. Data will be analysed using alpha and beta diversity metrics, differential abundance analyses and multivariate analyses to identify microbiome-based predictors of therapeutic response.

ETHICS AND DISSEMINATION

Ethical approval was received by the Research Ethics Board (REB) of University of British Columbia-Providence Healthcare (UBC-PHC) with a REB number H23-02927. All amendments to the protocol are reported and adapted based on the requirements of the REB. The results of this study will be submitted to peer-reviewed journals and will be communicated in editorials/articles by the IBD Centre of BC and BC Children's Hospital Research Institute.

TRIAL REGISTRATION NUMBER

NCT06453720.

PROTOCOL VERSION

2024-06-21, version 3.0.

Key Themes in the Care of Inflammatory Bowel Diseases Among Immigrant Populations: A Systematic Review

BACKGROUND

The care of inflammatory bowel disease (IBD) requires special attention among immigrants due to different disease incidence, phenotype, and risk profiles. We aimed to highlight key themes among existing literature to inform equitable care in all immigrants living with IBD.

METHODS

A systematic literature search was conducted in MEDLINE, EMBASE, the Cochrane library, Scopus, and ProQuest from inception to February 2023 to identify studies capturing the care of IBD among immigrants who moved from one country to another, irrespective of the timing of IBD diagnosis. Studies on immigrant children and children of immigrants were also included. We reported qualitative and quantitative data as reported in each individual study, and where applicable, we noted comparisons between immigrants and non-immigrants, defined as natives of the adopted country.

RESULTS

This review included 50 eligible studies. 12/19 (63.1%) studies reported lower incidence of IBD among immigrants, although rates increased from first- to second-generation immigrants in five studies. Most immigrants had significant changes in their diet after immigration, and their gut microbiota was different compared to non-immigrants. Immigrants had different environmental exposures and in certain populations, more severe IBD phenotypes and extra-intestinal manifestations (EIMs). Medical and surgical treatments were lower among immigrants in certain regions, although they had appropriate healthcare utilization and similar hospitalization rates compared to non-immigrants.

CONCLUSIONS

IBD care among immigrants is unique due to their different risk profiles and disease phenotypes, and the potential barriers with healthcare access. Understanding IBD among immigrants is key to ensure equitable care in this unique population.

Diverse Phenotypes, Consistent Treatment: A Study of 30 997 South Asian and White Inflammatory Bowel Disease Patients Using the UK Inflammatory Bowel Disease BioResource

BACKGROUND

Studies in the UK and North America have suggested a distinct disease profile in South Asians compared to that of White populations. Disparities in the medical and surgical management of IBD in minority ethnic groups (including Black Americans and Asians) in the US have been shown, while data from Europe, including the UK, have been lacking. This study sought to evaluate South Asian (SA) and White (WH) inflammatory bowel disease (IBD) phenotypes, and to explore treatment approach variations between these cohorts in the UK using the IBD BioResource database.

DESIGN

Differences between WH and SA IBD patients were analysed using demographic, phenotypic and outcome data. Drug utilisation patterns and surgical outcomes were assessed in propensity score-matched (PSM) cohorts with multivariable logistic regression, Cox regression and Kaplan-Meier analysis.

RESULTS

30,997 eligible patients were included. UC was the predominant disease subtype in SA (p<0.001). SA were younger at diagnosis (p<0.001), had a male preponderance (p<0.001), and were less likely to have a smoking history at diagnosis. The SA CD phenotype differed from WH, with less ileal (SA 30.3%, WH 38.4%, p=0.008) and stricturing (SA 16.9%, WH 25.6%, p<0.001) disease, but more perianal disease (SA 38.5%, WH 32.2%, p=0.009). More SA UC patients had extensive disease (SA 41.7%, WH 34.1%, p<0.001). In PSM cohorts, comparing treatments, there were no differences in 5-aminosalicylate, corticosteroid, thiopurine, anti-TNF or vedolizumab use. Survival analysis in matched cohorts showed no difference in time to surgery (CD) or colectomy (UC), and SA ethnicity was not associated with a difference in risk of surgery/colectomy.

CONCLUSION

Demographic and phenotypic differences exist between UK SA and WH IBD patients, highlighting distinct ethnicity-related variance, and the need for a research focus on under-represented populations. In comparing matched SA and WH patients, no disparity in medical and surgical IBD therapy in UK healthcare has been demonstrated: treatment is consistent regardless of ethnicity.

Bile Acids in Inflammatory Bowel Disease: From Pathophysiology to Treatment

Inflammatory bowel disease (IBD) is a chronic condition that affects about 7 million people worldwide, and new therapies are needed. Understanding the complex roles that bile acids (BAs) play in IBD may lead to the development of novel IBD treatments independent of direct immunosuppression. This review discusses the latest discoveries in the roles BAs play in IBD pathogenesis and explores how these discoveries offer promising new therapeutic targets to treat IBD and improve patient outcomes. Several therapies discussed include specific BA receptor (BAR) agonists, dietary therapies, supplements, probiotics, and mesenchymal stem cell therapies that have all been shown to decrease IBD disease activity.

Gut microbiome-associated predictors as biomarkers of response to advanced therapies in inflammatory bowel disease: a systematic review

Loss of response to therapy in inflammatory bowel disease (IBD) has led to a surge in research focusing on precision medicine. Three systematic reviews have been published investigating the associations between gut microbiota and disease activity or IBD therapy. We performed a systematic review to investigate the microbiome predictors of response to advanced therapy in IBD. Unlike previous studies, our review focused on predictors of response to therapy; so the included studies assessed microbiome predictors before the proposed time of response or remission. We also provide an update of the available data on mycobiomes and viromes. We highlight key themes in the literature that may serve as future biomarkers of treatment response: the abundance of fecal SCFA-producing bacteria and opportunistic bacteria, metabolic pathways related to butyrate synthesis, and non-butyrate metabolomic predictors, including bile acids (BAs), amino acids, and lipids, as well as mycobiome predictors of response.