Method for immobilizing a target microorganism or target chemical found in a mammal includes introducing into a gastrointestinal tract of the mammal immobilization particles including immobilization molecules capable of attaching to the target microorganism or the target chemical, which immobilization molecules are attached to one or more portions of a structure that is capable of inhibiting contact between tissues of the gastrointestinal tract and the target microorganisms or target chemicals attached to the immobilization molecules.
