Mammals cannot digest cellulose and ttherefore cannot directly obtain glucose from wood  Mushrooms can, however; and some mushrooms use cellulose to make highly branched polymers, the branches of which are a form of glucose called beta-glucans  Beta-glucan extracts from various types of mushrooms slow, reverse, or prevent the growth of cancerous tumors in mammals, and the antitumor activity of beta-glucans increases as the degree of branching increases
These extracts prevent tumor growth not by killing cancer cells directly but by increasing immune-cell activity
The greater the degree of branching of beta-glucans, the greater the degree of immune-cell activity it triggers in mammals.