Probiotic and Bioactive Compounds in Foods: From Antioxidant Properties to Gut Microbiota Modulation

Dietary bioactive compounds derived from plant-based and fermented foods act as plei-otropic modulators of human health, exerting antioxidant, anti-inflammatory, cardiopro-tective, neuroprotective, and metabolic effects beyond basic nutrition. Whole foods (fruits, vegetables, grains, nuts) provide synergistic mixtures of bioactives, whereas fermented foods generate a wide range of microbial-derived metabolites (peptides, organic acids) as well as probiotics that enhance nutrient bioavailability and support gut health. The gut microbiota plays a central mediating role in the biological effects of dietary bioactives through a dynamic, bidirectional interaction: dietary compounds shape microbial composition by promoting beneficial taxa and suppressing pathogens, while microbial metabolism converts these compounds into bioactive metabolites, including short-chain fatty acids, that profoundly influence host health. Despite their demonstrated health potential, the clinical translation of many dietary bioactives is limited by low bioavailability, which is influenced by digestion processes, food matrix and processing conditions, host genetics, and individual microbiota profile. Overcoming these limitations requires a deeper understanding of the synergistic interactions among dietary bioactives, probiotics, microbial metabolites, and host signaling pathways. This review provides an integrated perspective of the sources, mechanisms of action, and health effects of food-derived bioactive compounds and probiotic mediated effects, while highlighting current translational challenges and future directions for the development of effective functional foods and personalized nutrition strategies.