Functional fermented foods in public health nutrition: key biomolecular mechanisms, gut microbiota interactions, and implications for metabolic disease prevention.

Functional fermented foods are increasingly recognized in public health nutrition for their potential to reduce the burden of metabolic diseases through fermentation-derived bioactive biomolecules. Fermentation enhances the nutritional and functional properties of foods by generating peptides, short-chain fatty acids, organic acids, exopolysaccharides, enzymes, and transformed phytochemicals with antioxidant, anti-inflammatory, immunomodulatory, and metabolic regulatory activities. Despite growing interest, the biomolecular pathways linking these compounds to metabolic health, particularly through gut microbiota modulation, remain insufficiently clarified. This review focuses on representative functional fermented foods such as dairy, cereal, legume, vegetable, tea, and traditional mixed fermented foods and key fermentation-derived biomolecules, including bioactive peptides, short-chain fatty acids, polyphenols, exopolysaccharides and organic acids, with emphasis on their mechanistic roles in gut microbiota modulation and metabolic disease prevention. By linking biomolecular mechanisms with public health outcomes, it positions functional fermented foods as promising, sustainable tools for metabolic disease prevention and health promotion.