Ultra-Processed Food Consumption and Irritable Bowel Syndrome: Current Evidence and Clinical Implications

Irritable bowel syndrome (IBS) is a prevalent disorder of gut–brain interaction (DGBI) with an adverse impact on quality of life. The global consumption of ultra-processed foods (UPF) is rapidly increasing, and UPF intake has recently been linked to a wide range of metabolic and chronic diseases. The potential role of UPF consumption in the onset and symptom generation of IBS is emerging but remains unclear. This narrative review synthesizes epidemiological evidence on the association between UPF consumption and IBS, integrates mechanistic insights from experimental and clinical studies and suggests clinical implications based on the current state of knowledge. Observational studies suggest that higher UPF intake may be associated with increased risk of IBS, although the evidence base is limited and subject to methodological challenges. Mechanistic studies indicate that additives including emulsifiers and non-nutritive sweeteners can alter pathways relevant to IBS symptom generation, such as gut microbiota composition, impair intestinal barrier function and trigger low-grade inflammation. Current evidence supports a possible link between UPF consumption and IBS. Increasing overall dietary quality and reducing UPF intake are promising complementary strategies to established dietary interventions. Future intervention trials may provide insights into relevant biological mechanisms, particularly if such changes co-occur with symptom improvement.