Reishi, Chaga, Shiitake, Maitake: Beta-Glucans for Immunity

Medicinal mushrooms — reishi, chaga, shiitake and maitake — have been used in traditional Asian medicine for centuries. Their active compounds — beta-glucans and polysaccharides — modulate the immune system by increasing the activity of macrophages and natural killer cells. We break down each mushroom separately.

🌿 What are medicinal mushrooms

Medicinal mushrooms are a group of fungi rich in biologically active compounds. Unlike common culinary mushrooms, they are usually taken as extracts, powders or capsules. The main active compounds are beta-glucans, triterpenes and polysaccharides.

• Used in traditional Chinese and Japanese medicine for thousands of years.
• Beta-glucans stimulate innate immunity.
• Reishi triterpenes have adaptogenic properties.
• Available as powders, capsules and tinctures.

🧬 Beta-glucans: mechanism

Beta-glucans are polysaccharides made of glucose units. They are recognised by immune cells through the dectin-1 receptor, activating macrophages, neutrophils and natural killer (NK) cells. This strengthens defence against pathogens and supports immune balance.

• Activate innate immunity via dectin-1.
• Increase macrophage and NK-cell activity.
• Stimulate cytokine production.
• Act systemically, not only in the gut.

🍄 Reishi (ganoderma)

Reishi (Ganoderma lucidum) is one of the most studied medicinal mushrooms. In traditional medicine it is called the "mushroom of immortality". Reishi is rich in triterpenes (ganoderic acids) and polysaccharides, supporting immunity, sleep and stress adaptation.

• Rich in triterpenes and beta-glucans.
• Supports immunity and sleep quality.
• Adaptogen — helps with stress.
• Usually taken as an extract in capsules.

🪵 Chaga

Chaga (Inonotus obliquus) grows on birch trees. It is rich in melanin and antioxidants. Chaga is often taken as tea or powder. It is known for its antioxidant properties and immune support.

• Rich in melanin and antioxidants.
• Supports immunity and protects against oxidative stress.
• Taken as tea or extract.
• Does not contain large amounts of reishi triterpenes.

🥢 Shiitake

Shiitake (Lentinula edodes) is an edible mushroom widely used in cooking. It contains lentinan, a beta-glucan with studied immunomodulatory effects. Shiitake can be eaten as a regular mushroom, and its extract taken to support immunity.

• Contains lentinan, an immunomodulatory polysaccharide.
• Eaten as food and taken as extract.
• Supports immunity.
• Edible and affordable.

🌾 Maitake

Maitake (Grifola frondosa) is known as the "dancing mushroom". It is rich in beta-glucans and is studied for its effect on metabolism and immunity. Maitake supports the immune system and may affect blood sugar and lipids.

• Rich in beta-glucans.
• Studied for effects on metabolism.
• Supports immunity.
• Taken as extract or powder.

📊 Norms and dosages

How much in food

• Shiitake is edible: a 100 g portion gives a noticeable amount of polysaccharides, but extract is more concentrated.
• Reishi, chaga and maitake are rarely eaten — they are taken as supplements.
• Beta-glucan concentration is standardised in extracts, low in ordinary food.