Abstract: An engineered microorganism, which comprises one or more of a gene encoding an aromatic amino acid transaminase, a gene encoding phenylalanine dehydrogenase, a gene encoding phenylpyruvate decarboxylase, a gene encoding an aldehyde reductase, a gene encoding glutamate dehydrogenase, and a gene encoding a phenylalanine transport protein, or a functional equivalent thereof. The present invention also relates to a composition comprising the engineered microorganism; a method for using the engineered microorganism or the composition to alleviate and/or treat diseases and/or conditions associated with hyperphenylalaninemia; and use of the engineered microorganism or the composition in the preparation of medicaments or health products for treating diseases and/or conditions associated with hyperphenylalaninemia.