Agaricus bisporus, is one of the most commonly consumed mushrooms in the world and is now cultivated in more than 70 countries. Native to Europe and North America, the immature A. bisporus is either white and known as the white button mushroom, or brown and known as the chestnut mushroom. When mature, the larger and flatter looking mushroom is known as the portobello mushroom. Popular over the world, this mushroom is found in many different dishes. A. bisporus has a high level of protein in comparison with other mushrooms and is a rich source of B vitamins and various minerals. There is increasing interest in the use of mushrooms as immune modulators.

Biological activities of A. bisporus have been explained by its polysaccharides, containing (1→6), (1→4)-linked α-glucan, (1→6)-linked β-glucan, and mannogalactin. These polysaccharides could modulate pro-inflammatory cytokines by both increasing and decreasing expressions in different conditions. Other research demonstrated that polysaccharides extracted from A. bisporus exhibited an anti-oxidant effect and showed the potential to prevent age-related disease with hepatoprotective effects.