Saccharomyces is a genus of fungi, or yeast, which comprises several different species. Interestingly, Saccharomyces yeasts are the most researched Eukaryote after humans! Eukaryotic means that the cells contain a nucleus with genetic material in it, which bacteria do not have. Yeasts are larger than bacteria and typically, Saccharomyces have a diameter of 2-8μm and length of 3-25μm. They are unicellular and either globose, ellipsoid or elongate in shape. Multilateral (multipolar) budding is typical. Saccharomyces are saprophytic which means that their digestion is extracellular. This is a process by which they secrete enzymes through their cell membrane wall; the enzymes then break down and digest food into molecules, which are then small enough to be taken up by passive diffusion or phagocytosis.

The probiotic species from this genus is called Saccharomyces boulardii, which is now extensively used as a probiotic supplement. This is very closely related to, and is classified with, the yeast species Saccharomyces cerevisiae, strains of which are extensively used in food production. Most people know Saccharomyces cerevisiae as brewer’s and baker’s yeast; a particular characteristic of yeasts is that they convert sugar into carbon dioxide and alcohol, making them ideal to be used to ferment the sugar in baked goods, and in alcohol production. In fact, just one yeast cell can ferment up to its own weight of glucose in just one hour. Other species such as Saccharomyces paradoxusSaccharomyces bayanus and Saccharomyces uvaruium are also used in beer and wine making.

As some properties & benefits of probiotics may be strain-specific, this database provides even more detailed information at strain level. Read more about the strains that we have included from this genus below.

Saccharomyces strain: Saccharomyces cerevisiae boulardii

For more insights and professional updates on probiotics, please visit the Probiotic Professionals pages.


Bekatorou A. et al., (2006), ‘Production of Food Grade Yeasts’. Food Technology Biotechnology, 44:407-415.
Landry C.R. et al., (2006), ‘Ecological and evolutionary genomics of Saccharomyces cerevisiae’. Molecular Ecology. (15):575-591.
Mortimer R.K., (2000), ‘Evolution and Variation of the Yeast (Saccharomyces) Genome". Genome, 10:403-409.
van Dijken, J.P., et al., (2000), ‘An interlaboratory comparison of physiological and genetic properties of four Saccharomyces cerevisiae strains’. Enzyme and Microbial Technology, 26:706-714.

Information on this genus was gathered by Joanna Scott-Lutyens BA (hons), DipION, Nutritional Therapist; and Kerry Beeson, BSc (Nut.Med) Nutritional Therapist.

Last updated - 18th September, 2018