Eastern European Fermented Foods: Nutritional Value, Functional Potential, and Cultural Heritage

Background: Fermentation is among the oldest and most versa-tile food processing techniques, enhancing not only shelf life but also nutritional and functional value. While Asian and Western fermented foods are extensively studied, traditional Eastern European fermentations—such as sauerkraut, kefir, bryndza, kvass, and sourdough—remain underexplored, despite their enduring cultural and dietary importance. These foods combine spontaneous or mixed-culture fermentations, diverse substrates, and unique microbial consortia that may yield distinct bioactive pro-files with potential health benefits. Methods: This narrative review synthesizes data from scientific articles, regional reports, and ethnographic sources retrieved from PubMed, Scopus, and Google Scholar up to 2025. Studies were selected for relevance to composition, microbiology, bioactive compounds, and human or experimental health outcomes related to Eastern European fermented foods. Results: Evidence indicates that traditional fermented dairy, ce-real, and vegetable products contain bioactive peptides, poly-phenols, vitamins, organic acids, and live or non-viable micro-organisms contributing to antioxidant, antihypertensive, immunomodulatory, and metabolic effects. Mechanistic studies support the generation of ACE-inhibitory peptides, microbial vitamins, and prebiotic/postbiotic compounds. However, variability in artisanal production and the scarcity of standardized human trials limit definitive conclusions. Conclusions: Eastern European fermented foods represent a culturally unique yet scientifically under characterized component of functional nutrition. Their complex microbial ecosystems and diverse substrates offer valuable models for studying diet–microbe interactions. Further omics-based and clinical research is warranted to clarify bioavailability, mechanisms of action, and their potential integration into evidence-based dietary strategies.