Pharmacoepigenetic Biomarkers in Inflammatory Bowel Diseases: A Narrative Review.

Inflammatory bowel disease (IBD), encompassing Crohn's disease (CD) and ulcerative colitis (UC), is a chronic, autoimmune disorder characterized by inflammation along the gastrointestinal tract. Global prevalence of the disease is increasing and patients often experience delays in diagnosis accessing effective therapy, highlighting an urgent need to develop a predictive biomarker for therapeutic response to reduce healthcare costs and disease burdens. Despite the advances to identifying genetic biomarkers for prediction of disease remission in IBD, patient responses vary widely, suggesting that inherited genetic variations alone cannot account for these differences. As autoimmune diseases like IBD are largely environmental in etiology, epigenetic modifications like DNA methylation, histone modifications, and non-coding RNAs (ncRNAs) also have the potential to be candidates for predictive biomarkers of patient disease development and treatment response. This review will explore the novel field of pharmacoepigenetics and the development of predictive epigenetic biomarkers for treatment response in IBD, highlighting new research in the field. While research is still in the early stages, the studies reviewed have demonstrated that epigenetic profiling can be utilized to predict treatment response in IBD patients. Additional pharmacoepigenetic cohorts with more diverse participants could help enhance current models, improving predictability of treatment response and clinical outcomes. As research in this field progresses, epigenetic biomarkers should be integrated into the clinical environment to expedite diagnosis, reduce trial-and-error approach to treatment, and lay the foundations for individualized therapeutic strategies for IBD patients.