What are some side effects of brewer's yeast?

The most common side effects of taking brewer's yeast include migraine-like headaches, bloating and gas, states Healthline. Some individuals who are allergic to brewer's yeast may experience difficulty breathing, throat tightness, or chest pain or tightness, and should seek immediate medical attention.

Some people take brewer's yeast, which is rich in several B vitamins and other minerals, as a nutritional supplement to enhance energy levels and support the immune system, explains Healthline. It is also a probiotic that aids in digestion and may be useful for treating diarrhea.

Made from Saccharomyces cerevisiae, a one-celled fungus, brewer's yeast is also an ingredient used to make beer and bread.