Food applications of probiotic yeasts; focusing on their techno-functional, postbiotic and protective capabilities

Probiotic yeasts (PYs) as promising cell factories and nutraceutical carriers have several pivotal potentials including health-promoting and bio-therapeutic effects (prevention and treatment of gastrointestinal infections, type II diabetes and several cancers, adjusting intestinal microbiota, supporting healthy mucosal and immune system functions), nutraceutical capabilities (cholesterol assimilation, degradation of unwanted/anti-nutrient compounds and production of antioxidants or increase of their bioavailability), and improvement of food quality and safety (biological control of foodborne bacteria and fungi, degradation and removal of mycotoxins and bacterial toxins, food bio-fortification and increase of the sensory scores). This review describes recent cutting-edge research findings about promising techno-functional and protective capabilities of PYs in the food matrices. Furthermore, important criteria such as bioprocess optimization and metabolomics findings, postbiotic capabilities and rare side effects reported for PYs are also discussed. Our study offers an overview concerning miraculous potentials of PYs, and it summarizes their metabolites and action mechanisms. Key findings and conclusions: Proper adhesion properties, antimicrobial effects, inherent antibiotic resistance and high adaptability to stressful environments are some of the most important capabilities of PYs. They can be used as starter/adjunct or co-cultures as alone or in combination with lactic acid bacteria to produce a variety of innovative probiotic or functional foods. Furthermore, these superior pro-functional cultures can produce several multifunctional metabolites such as folates, mycocins, prebiotic oligosaccharides, exopolysaccharides, enzymes, antioxidants and volatile compounds with wide and interesting activities in medical, biotechnology and food industries. • Postbiotic capabilities of probiotic yeasts affect food quality and safety. • Probiotic yeasts have been applied to develop bio-fortified functional foods. • Metabolomics revealed multifunctional metabolites of probiotic yeasts. • Probiotic yeasts possess protective activity against foodborne biohazards.