Abstract
Purpose: To illustrate the hypothesis that alterations in mucosal glycosylation, particularly O‐glycosylation, may result in altered interaction with carbohydrate‐binding proteins (lectins) in the diet.
Design & methods: A summary of recent literature focussing on work by the author's group demonstrating in vitro and in vivo lectin–epithelial interactions, particularly in the colonic epithelium.
Results: Similar alterations in O‐glycosylation occur in the colonic epithelium in inflammatory diseases and in cancer. They include shortening of O‐glycans and increased expression of onco‐fetal carbohydrate antigens. Peanut lectin, which selectively binds the TF antigen, is shown to survive transit through the intestine and to cause significantly increased epithelial proliferation. Other lectins inhibit proliferation, e.g. edible mushroom lectin which becomes internalised and blocks nuclear‐localising‐sequence‐dependent nuclear protein import.
Conclusions: Intestinal epithelial glycosylation is commonly altered in inflammation and cancer and we are only just beginning to understand the implications that this may have for interaction with carbohydrate‐binding proteins that could originate from the diet, the gut microbiota or the host.