A Systems Biology Approach for Identification of Host and Microbial Mechanisms and Druggable Targets for the Treatment of PSC-IBD

Study Overview
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Brief Summary
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Primary sclerosing cholangitis (PSC) is the classical hepatobiliary manifestation of inflammatory bowel disease (IBD). Although rare, PSC is associated with significant and disproportionate unmet needs; with heightened risks of colorectal cancer and colectomy, and greater all-cause mortality rates compared to matched IBD patients. Unfortunately, no medical therapy has been proven to slow disease progression in PSC-IBD, and liver transplantation is the only lifesaving intervention for patients. The strong association between PSC and IBD has led to several pathogenic hypotheses, in which dysregulated mucosal immune responses are proposed to contribute. Of note, the investigators recently identified distinct mucosal transcriptomic profiles in PSC-IBD; with regards bile acid metabolism, bile acid signalling, and a central role of enteric dysbiosis. In parallel, pilot data from other groups have shown that treatment with oral vancomycin (a non-absorbable, gut-specific antibiotic) attenuates colonic inflammation and improves biochemical markers of cholestasis in PSC. However, there is no mechanistic data exploring the host-microbial alterations under vancomycin treatment in PSC-IBD, neither the impact of vancomycin on bile acid circulation. The investigators of this study hypothesize that oral vancomycin attenuates colonic mucosal inflammation in PSC-IBD, by restoring gut microbiota mediated bile acid homeostatic pathways. Through these means the study aims to identify druggable gut microbial and host molecular pathways associated with bile acid mediated colonic mucosal inflammation in PSC-IBD.

Detailed Description
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Primary sclerosing cholangitis (PSC) is the classical hepatobiliary manifestation of inflammatory bowel disease (IBD). Although rare, PSC is associated with significant and disproportionate unmet needs; with heightened risks of colorectal cancer and colectomy, and greater all-cause mortality rates compared to age- and sex-matched IBD controls. Unfortunately, no medical therapy has been proven to slow disease progression in PSC-IBD, and liver transplantation is the only lifesaving intervention for patients. The strong association between PSC and IBD has led to several pathogenic hypotheses, in which dysregulated mucosal immune responses are proposed to contribute. Of note, the investigators of this study recently identified distinct mucosal transcriptomic profiles in PSC-IBD; with regards bile acid metabolism, bile acid signalling, and a central role of enteric dysbiosis. In parallel, pilot data from other groups have shown that treatment with oral vancomycin (a non-absorbable, gut-specific antibiotic) attenuates colonic inflammation and improves biochemical markers of cholestasis in PSC. However, there is no mechanistic data exploring the host-microbial alterations under vancomycin treatment in PSC-IBD, neither the impact of vancomycin on bile acid circulation. In this study, fifteen PSC-IBD patients will be recruited through a large tertiary referral centre, who are undergoing lower gastrointestinal examination as per routine standard of care. Participants will be offered 4 weeks of treatment with oral vancomycin, and stool samples collected at different timepoints to evaluate changes in metagenomic, metatranscriptomic, and bile acid profiles. Colonic biopsies will be collected at baseline and at week 4 (flexible sigmoidoscopy) and subjected to FACS sorted RNA sequencing to identify changes in colonic epithelial cell pathways. Multi-omics data integration will be performed to uncover combinations of predictive profiles, model microbial networks, and host transcriptomic changes implicated in the response to oral vancomycin. This study will inform the downstream identification of specific host molecular and microbial pathways that has a potential for development of therapeutic targets for PSC-IBD in clinical practice.

Official Title
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A Systems Biology Approach for Identification of Host and Microbial Mechanisms and Druggable Targets for the Treatment of PSC-IBD

Conditions
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Inflammatory Bowel Diseases, Primary Sclerosing Cholangitis

Intervention / Treatment
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* Drug: Oral Vancomycin


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients with confirmed diagnosis of primary sclerosing cholangitis and concurrent colitis Mild to moderately active colitis based on partial Mayo score of ≥3 and ≤6 Scheduled for a standard of care lower GI endoscopy as part of disease assessment / surveillance Exclusion Criteria: History of previous colectomy Isolated small bowel disease Stricturing , fistulating or perianal phenotype Use of antibiotics and/or probiotics in the prior 3 months Use of steroids in last 2 weeks Commenced thiopurines / methotrexate in last 3 months History of intolerance to oral vancomycin Decompensated liver disease (Child C cirrhosis) Active infectious diarrhoea

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Intervention/Treatment |
| --- |
|Drug: Oral Vancomycin|As part of standard of care|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Identify stool metagenomic, metatranscriptomic and bile acid profiles following treatment with oral vancomycin in PSC-IBD |  | 12 months | 
| Investigate changes in colonic mucosal epithelial bile acid and immunological pathways through FACS sorted RNA-sequencing following oral vancomycin |  | 12 months | 
| Identification of druggable host molecular and microbial targets through multi-omic integration analysis |  | 12 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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primary sclerosing cholangitis, inflammatory bowel disease, microbiome, vancomycin