Brewer’s yeast, also known as Saccharomyces cerevisiae, is commonly used in baking and the fermentation of beer; hence, the common name. Brewer’s yeast is rich in nutrients like chromium, B vitamins, protein, selenium, potassium, iron, zinc, and magnesium. It is the byproduct of beer brewing and can be grown on hops. Hops are the dried flowers that give beer its bitter taste. The yeast is separated from the beer after fermentation and processed. Aside from hops, the yeast can also be cultivated on other plants, like sugar beets.

Brewer’s yeast, along with its close cousin Saccharomyces boulardii, is considered a probiotic. Probiotics are foods or dietary supplements that contain organisms, like bacteria or yeast, which provide health benefits for humans. Along with brewer’s yeast, another example of a probiotic is yogurt with live and active bacteria cultures.

Bacteria and yeasts naturally live in our bodies, mainly in the digestive tract. Probiotics contain “good” bacteria or yeasts that keep our digestive tract functioning properly, as well as keeping the population of harmful or “bad” organisms low.1 The probiotic activity of S. boulardiiin particular has been studied in the treatment of a number of conditions including:2,3,8

In addition to its probiotic benefits, Brewer’s yeast has been used as a protein supplement and is promoted as an energy and immunity enhancer.

This article covers both S. cerevisiae and S boulardii.

Brewer’s yeast is usually sold in the form of a powder, flakes, liquid, or tablets. It can also be found as part of other food products, like fermented milks.7