A number of pre-clinical and clinical studies indicate that nutritional yeasts as well as Saccharomyces boulardii are important products for prophylactic and/or therapeutic purposes. Nutritional yeasts are a rich source of amino acids, single cell proteins, several bioavailable minerals (e.g. chromium, selenium, zinc, iron, magnesium, cooper, manganese), and B vitamins. The properties of these non-infectious yeasts may be of particular importance for human and animal health. Amongst them, Saccharomyces cerevisiae is the best-known species used as a source of B vitamins and nutrients, especially chromium and selenium incorporated as organic compounds. Chromium is necessary for the maintenance of normal blood glucose levels, while selenium promotes a normal function of immune system. Another less-known species is Yarrowia lipolytica, which contributes to the production of a number of important nutritional elements, including bioavailable proteins, essential amino acids, minerals, organic acids, polyalcohols, carotenoids, aroma compounds, single cell oil, and microbial surfactants. Nutritional yeasts are beneficial for vegans, vegetarians, athletes, reconvalescents, as well as young people during the puberty period. Furthermore, some yeast species possess properties required for a microorganism to be considered as probiotic. One of them is S. boulardii, particularly recommended in antibiotic-associated diarrhoea and recurrent Clostridium difficile intestinal infections.
Keywords: nutritional yeasts, Saccharomyces cerevisiae, Saccharomyces boulardii, Yarrowia lipolytica, probiotics