Shiitake mushrooms are the third-most popular mushroom in the world, after oyster and white button. Shiitake mushrooms contain eritadenine, a compound known to reduce cholesterol levels in the blood. They also contain beta-glucans that reduce inflammation and help prevent the intestines from absorbing cholesterol. They also are rich in polysaccharides like lentinans and other beta-glucans. These compounds protect against cell damage, help your immune system, and boost white blood cell production for fighting off microbes. Polysaccharides also have anti-inflammatory properties.