Beta-glucan is a type of soluble fiber found in the cell walls of certain grains, fungi, and yeast. It is known for its potential health benefits, including supporting the immune system and lowering cholesterol levels. Common sources of beta-glucan include oats, barley, and mushrooms. Research suggests that beta-glucan may help improve heart health by reducing cholesterol absorption in the intestines. Additionally, it may enhance the body's immune response by activating certain immune cells. Overall, incorporating beta-glucan-rich foods into your diet can contribute to better health and well-being.