OLD DOGMA. “According to the standard paradigm large macromolecules consumed with food cannot pass directly to the circulatory system. During digestion proteins and DNA are thought to be degraded into small constituents, amino acids and nucleic acids, respectively, and then absorbed by a complex active process and distributed to various parts of the body through the circulation system.”
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0069805