Postbiotics and Short-Chain Fatty Acids (SCFAs) in the Pathophysiology of Digestion: A New Therapeutic Concept

This article examines the role of postbiotics and short-chain fatty acids (SCFAs) in the physiology and pathophysiology of the digestive system and their cellular and molecular mechanisms of action. Particular attention is paid to how microbiota-derived metabolites regulate the intestinal epithelial barrier, local immunity, inflammation, energy metabolism and metabolic homeostasis. The mechanisms through which the major SCFAs—acetate, propionate and butyrate—support colonocyte energy supply, tight-junction function, G-protein-coupled receptor signalling and the modulation of histone deacetylase activity are discussed, together with the effects of postbiotics (inactivated microorganisms and/or their components) on epithelial protection, immune reactivity and intestinal microecology. The pathogenetic links between dysbiosis, increased intestinal permeability, inflammation and metabolic dysfunction are analysed in relation to inflammatory bowel diseases, irritable bowel syndrome, antibiotic-associated microbiota changes, obesity and insulin resistance. Drawing on research published in 2025–2026, the article considers the therapeutic prospects of postbiotics and SCFAs, criteria for assessing their efficacy and safety, and the limitations of translating experimental findings into clinical practice, including individual microbiota variability, the need to standardise preparations and the demand for high-quality clinical trials.