Targeting Intestinal Inflammation in Ulcerative Colitis Through Polyphenol and Fiber Interactions

<p dir="ltr">Ulcerative colitis (UC) is a chronic inflammatory bowel disease characterized by dysregulated immune responses, impaired barrier integrity, and persistent colonic inflammation. Emerging evidence suggests that interactions between dietary polyphenols and soluble fibers may enhance the stability, delivery, and bioactivity of bioactive compounds, offering a novel nutritional strategy for managing UC. However, most research evaluates anthocyanins and fibers independently, without addressing the potential synergistic benefits of their interaction. This thesis addresses this gap by examining a whole-matrix blueberry anthocyanin–pectin complex using integrated <i>in vitro</i> and <i>in vivo</i> models.</p><p dir="ltr">The first study investigated digestive stability and protective efficacy in DSS-induced colitis. <i>In vitro</i>, complexation with pectin improved anthocyanin stability, antioxidant capacity, and predicted colonic delivery. <i>In vivo</i>, IL-10 knockout mice supplemented with the complex exhibited preserved colon length, enhanced barrier function, and reduced pro-inflammatory cytokine expression, while also mitigating gastrointestinal intolerance observed with isolated pectin.</p><p dir="ltr">The second study evaluated therapeutic potential in a piroxicam-induced chronic colitis model. The complex enhanced the anti-inflammatory effects compared to the blueberry anthocyanins alone, reducing distal colonic <i>Il17 </i>expression and lowering serum lipocalin-2, indicating both localized and systemic improvements.</p><p dir="ltr">Collectively, these findings demonstrate that polyphenol–fiber complexation can enhance colonic bioefficacy and immune modulation in UC. This work supports the emerging concept of food matrix engineering as a dietary strategy to modulate mucosal inflammation and highlights the therapeutic promise of polyphenol–fiber interactions in inflammatory bowel disease management.</p>