Brewer's yeast is used for diarrhea, the common cold and other upper respiratory tract infections, influenza, swine flu, 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 insulinmore effectively and this can lower blood sugar levels.
Additionally, brewer's yeast seems to stimulate chemicals (intestinal enzymes) that could help relieve diarrhea.
It 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.