Ultra-Processed Foods, Gut Microbiota, and Inflammatory Bowel Disease: A Critical Review of Emerging Evidence

Inflammatory bowel diseases (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), are chronic conditions marked by dysregulated inflammation in the gastrointestinal tract. Although the pathophysiology of IBD remains incompletely understood, it involves complex interactions between genetic predisposition and environmental triggers, such as gut microbiota imbalances and immune dysfunction, leading to chronic inflammation and mucosal injury. IBD affects approximately 7 million individuals globally, with prev-alence increasing in Europe, North America and Oceania. This rise parallels the growing consumption of ultra-processed foods (UPF), which are typically rich in sugars, fats, and additives but low in fiber, vitamins, and other essential nutrients. High UPF consumption is associated with intestinal dysbiosis, marked by reduced microbial diversity, decreased short-chain fatty acid production, impaired barrier integrity, and mucus layer disruption. These alterations may promote immune-mediated diseases, including IBD, where dysbio-sis is often characterized by an overgrowth of pathogenic bacteria such as Clostridium and Enterococcus, ultimately triggering inflammatory responses in the host. Considering these associations, this review critically examines the influence of UPF consumption on gut mi-crobiota composition and function, and its potential link to IBD.