To test that mushrooms are not very digestible unless cooked, try this self-experiment.
Appreciate everyone's comments. Here is a simple test you can all try: Take a small "Button", closed cap, fresh, uncooked shiitake mushroom, and swallow it whole in the afternoon. The next morning, check your stool, and you will find the mushroom fully intact. (Yes, I have done this !) Now take a similarly sized mushroom (not the same mushroom --- No, I have not done this !), and boil it in water for 10 minutes. Swallow that one, and you will not see any evidence of mushrooms in your stool the next morning. Of course, everyone's digestive systems are different, but generally, most of us will see that this is true.
If you use a high speed blender and lyse the cells, then you can release the nutrients contained within the mushrooms, but you won't destroy the resident toxins. For instance, two oyster mushrooms, the King Oyster (Pleurotus eryngii) and the common Oyster mushroom (Pleurotus ostreatus) contain toxins which are quickly broken down with heat. Hemolysin and ostreolysin are two blood cell-destroying toxins. Consuming these mushrooms raw, even though you have put them through a blender, means these toxins are still present. Make sure your mushrooms and mushroom supplements are cooked - consumng them raw puts you into the danger zone. I am especially concerned about companies selling raw mushroom powders - in fact, be sure to check the ingredients. Some companies are selling raw King Oyster mushrooms, apparently unaware of the science showing the dangers of the heat sensitive hemolysin andostreolysin! Yikes!
In terms of psilocybin mushrooms, they can be eaten fresh or lightly cooked. Ones picked from manure or co-cultivated with lots of molds and bacteria, are better boiled in water for a few minutes, although the heat may reduce potency to a degree, absorption is increased, and other toxins are reduced. The more you chew, the more the cells are broken and the water soluble compounds can be absorbed. Obviously, people do not eat psilocybin mushrooms for nutrition, unless you consider psilocybin a nutrient for your soul.
Safety first - nature is a number's game. This advice is to help you tilt the balance in the favor of good health and a more positive outcome. Hope this helps!