Intestinal absorption of proteins and macromolecules and the immunological response.

Progress in the field of biotechnology has renewed interest in the oral delivery of macromolecules, in particular, proteins and peptides. While small quantities of proteins may be absorbed from the gastrointestinal tract intact, enzymatic degradation and poor absorption have historically limited protein administration to the parenteral route. By consideration of the mechanisms of macromolecular absorption from the gut, it may be possible to exploit physiological processes to promote protein uptake. However, the response of the immune system to intestinally absorbed antigen may limit the oral delivery of proteins but could provide an attractive alternative to parenteral immunization.