Brewer's yeast is a kind of yeast that is a by-product of brewing beer. Dietary supplements containing brewer's yeast often contain non-living, dried yeast. People use brewer's yeast to make medicine.
Brewer's yeast is taken by mouth for respiratory problems, including the common cold and other upper respiratory tract infections, influenza, seasonal allergies, and swine flu. Brewer's yeast is also taken by mouth for diarrhea, swelling of the colon (colitis) due to the bacteria Clostridium difficile, high cholesterol, loss of appetite, acne, premenstrual syndrome (PMS), recurring boils on the skin (furunculosis), and type 2 diabetes. It has also been used as a source of B vitamins, chromium, and protein.
Due to the chromium content of brewer's yeast, there is interest in using it for lowering blood glucose in people with diabetes. Chromium may help the body use insulin more effectively. This can lower blood sugar levels.
Additionally, brewer's yeast seems to stimulate chemicals (intestinal enzymes) that could help relieve diarrhea.
Brewer's yeast also might help fight bacteria that cause infections in the intestine, as well as improve the body's defenses against viral lung infections such as flu and the common cold.
Brewer's yeast is a source of B vitamins and protein.