Postbiotics and parabiotics derived from bacteria and yeast: current trends and future perspectives

The benefits of probiotics in foods are well-studied, but maintaining their effectiveness requires survival through various stress conditions like processing, storage, and digestion. Safety concerns, such as antibiotic resistance and potential infections, have raised questions about using live probiotics. Although traditionally, probiotic foods require live microorganisms for beneficial effects, research suggests that inactivated (non-viable) probiotic cells and their metabolic byproducts can also provide health benefits. This has led to the introduction of terms like postbiotics (cell-free metabolic byproducts of probiotics) and parabiotics (inactivated probiotic cells and cell compounds). Most studies focus on Lactic Acid Bacteria (LAB) as sources of postbiotics and parabiotics, but there is limited research on yeast-derived compounds. Yeasts can produce diverse metabolites and unique intracellular components, potentially enhancing shelf-life, sensory qualities, safety, and health benefits in food products. This review explores the advances in bacterial and yeast postbiotics and parabiotics and their applications in food, pharmaceuticals, and feed systems.