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

BACKGROUND/AIMS: Inflammatory bowel diseases (IBDs), 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 prevalence increasing in Europe, North America, and Oceania. This rise parallels the growing consumption of ultra-processed foods (UPFs), which are typically rich in sugars, fats, and additives but low in fiber, vitamins, and other essential nutrients. These associations, this review critically examines the influence of UPF consumption on gut microbiota composition and function and its potential link to IBD. METHODS: A bibliographic search was conducted in the SciELO, PubMed, and Cochrane databases. RESULTS AND CONCLUSIONS: 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 dysbiosis is often characterized by an overgrowth of pathogenic bacteria such as <i>Clostridium</i> and <i>Enterococcus</i>, ultimately triggering inflammatory responses in the host.