Volume 30, Issue 172, June 2026

Interactions between diet, gut microbiota, and immune response in inflammatory bowel disease

Katarzyna Jucha^1♦, Kacper Paczosa², Wiktoria Mikulska², Julia Wilanowska², Aleksandra Borkowska³, Zuzanna Kawa¹, Patrycja Patronik¹

¹Faculty of Medicine, Collegium Medicum, University of Rzeszów, Rzeszów, Poland
²Faculty of Medicine, Medical University of Silesia, Katowice, Poland
³Faculty of Medicine University of Warmia Mazury in Olsztyn, Olsztyn, Poland

^♦Corresponding author
Katarzyna Jucha, Faculty of Medicine, Collegium Medicum, University of Rzeszów, Rzeszów, Poland

ABSTRACT

Inflammatory bowel disease (IBD) is a chronic disease associated with recurrent inflammation of the gastrointestinal tract. Recent studies indicate that diet and gut microbiota have an important influence on the development of the disease, its course, and treatment effectiveness. This review summarizes knowledge about diet function in a comprehensive review of current literature concerning the relationship between nutrition, gut microbiota composition, intestinal barrier integrity, and inflammatory activity in patients with IBD. The analyzed studies showed that disturbances in the composition of gut microbiota, known as dysbiosis, are one of the main factors involved in IBD development. Dysbiosis is characterized by lower microbial diversity, a reduced number of beneficial bacteria producing short-chain fatty acids (SCFAs), and an increased number of microorganisms that may promote inflammation. Special attention has been given to butyrate-producing bacteria because butyrate helps maintain the integrity of the intestinal barrier and supports proper immune system function. The review also describes the effects of pharmacological treatment, including biologic therapies and aminosalicylates, on reducing inflammation and restoring microbial balance. We have highlighted the diet as one of the most important nutritional principles for patients with inflammatory bowel disease (IBD). A diet rich in fruits, fiber, omega-3 fatty acids, legumes, vegetables, and fermented foods supports the growth of beneficial gut bacteria and supports the functioning of the intestinal barrier. However, Western diets and the consumption of processed foods can exacerbate dysbiosis, increase intestinal permeability, and promote inflammation.

Keywords: Inflammatory bowel disease, Crohn’s disease, Microbiota, Ulcerative colitis, Mediterranean diet

Medical Science, 2026, 30, e102ms3895

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Published: 15 June 2026