Gut Microbiota and Nutritional Aspects in Pancreatic Diseases: A Narrative Review

Pancreatic diseases, including acute pancreatitis (AP) and chronic pancreatitis (CP), pancreatogenic diabetes mellitus (T3cDM), autoimmune pancreatitis (AIP), and pancreatic cancer (PDAC), are associated with metabolic, inflammatory, and nutritional disturbances. Increasing evidence indicates a bidirectional relationship between pancreatic diseases and the gut microbiota. On the one hand, alterations in microbial composition and function, intestinal barrier dysfunction, and bacterial translocation may contribute to their pathogenesis and progression. On the other hand, pancreatic diseases and associated changes in nutrition and treatment may affect the composition and function of the gut microbiota. This narrative review aimed to discuss the role of the gut microbiota and nutritional aspects in selected pancreatic diseases. PubMed/MEDLINE was searched up to May 2026 for English-language publications, with emphasis on studies from the previous 10 years, while earlier relevant studies were also considered. Google Scholar was used as a supplementary source. Human observational, experimental and mechanistic studies, as well as secondary literature, were considered, addressing pancreatic microbiota, intestinal permeability, bacterial translocation, nutrition, and microbiota-targeted interventions. Available evidence indicates that pancreatic diseases are associated with alterations in gut and pancreatic microbial communities, although the reported patterns vary between diseases and studies. These changes may be relevant to intestinal barrier integrity, inflammatory signaling, microbial metabolite production, and, in pancreatic cancer, the tumor microenvironment and treatment response. Nutritional management remains an important component of care, particularly in patients with exocrine pancreatic insufficiency and those at risk of malnutrition. However, the causal relationships between pancreatic diseases and microbiota alterations remain incompletely established, and evidence for microbiota-targeted interventions is limited and heterogeneous. Further clinical studies are needed to clarify these interactions and their potential diagnostic and therapeutic relevance.