What is the difference between mushroom fruiting body and mycelium?

A fruiting body is generally what you would visually recognize as a mushroom. It is fleshy, contains spores, and grows above ground or directly on the surface of its host, like a tree or old log. The mushroom's fruiting body comprises a stem, cap , and gills. Mycelium is the main body and feeding membrane of a mushroom. It grows underground or within the host plant. Mycelium is the stage that produces a mushroom but it is not a mushroom.


Fruiting bodies are considered “full-spectrum” as they provide a wider array of the mushroom's nutritional compounds. Fruiting body extracts contain higher concentrations of bioactive components, especially beta-glucans. Normally, mycelium-based products contain 50%-80% starch from the growing substrate, up to 50% less beta-glucans than the products from mushroom fruiting bodies, and far less beneficial compounds. Mycelium was primarily created as a cheaper alternative that was quicker to produce by industrial fermentation.


*According to the FDA, mycelium has an identity different from actual mushrooms.