Looking for celiac information; wondering about growing Shitake mushrooms using rye...?

The mushrooms are saprophytes and they live off from the nutrients they get from the rye but, like animals, they have enzymes to digest the fats, carbohydrates, and proteins that the feed on. So if the mushroom lives off the proteins of rye they would be breaking proteins down into lesser poly peptides or amino acids before absorbing them into their bodies. It is my opinion that by the time the protein's product is adsorbed into the mushroom it would be in another form either a lesser polypeptide or amino acid.