; (B) is intended to— (i) affect the byproducts of the digestive process of an animal; (ii) reduce the presence of foodborne pathogens of human health significance in an animal intended to be used for food; or (iii) affect the structure or function of the body of the animal, other than by providing nutritive value, by altering the animal’s gastrointestinal microbiome; and (C) achieves its intended effect by acting solely within the gastrointestinal tract of the animal. (2) Such term does not include a substance that— (A) is intended for use in the diagnosis, cure, mitigation, treatment, or prevention of disease in an animal; (B) is a hormone; (C) is an active moiety in an animal drug, which, prior to the filing of a petition under section 409 was approved under section 512, conditionally approved under section 571, or indexed under section 572, or for which substantial clinical investigations have been instituted and for which the existence of such investigations has been made public; (D) is an ionophore; or (E) is otherwise excluded from the definition based on criteria established by the Secretary through notice and comment rulemaking. (3) A zootechnical animal food substance shall be deemed to be a food additive within the meaning of paragraph (s) and its introduction into interstate commerce shall be in accordance with a regulation issued under section 409. A zootechnical animal food substance shall not be considered a drug under paragraph (g)(1)(C) solely because the substance has an intended effect described in subparagraph (1). . (b) Food additives Section 409 of the Federal Food, Drug, and Cosmetic Act ( 21 U.S.C. 348 ) is amended— (1) in subsection (b)— (A) by redesignating paragraphs (3) through (5) as paragraphs (4) through (6), respectively