Characteristics and consequences of interactions of lectins with the intestinal mucosa.
Lectins are essential and omnipresent plant (glyco)protein constituents and are ingested daily in appreciable amounts by both humans and animals. As they are biologically highly active, their consumption may have serious consequences for metabolism and health. Lectins, by virtue of their stability and specific recognition and binding by gut brush border epithelial cells, are potent exogenous metabolic growth signals for the gut and the body. As a result of their binding to surface glycans they may affect the turnover and loss of epithelial cells, damage the luminal membranes of the epithelium, interfere with their digestive/absorptive activities, stimulate shifts in the bacterial flora and modulate the immune state of the digestive tract. When eaten in relatively large quantities, these lectins have appreciable antinutritive effects for the consumers. In contrast, lectins which are not bound by the mucosa usually induce little or no harmful effects. From recent studies it is now realized that in addition to the major and sometimes dramatic effects of lectins on the gut which are mediated through their binding to pre-existing membrane glycosyl groups, lectins as metabolic signals, can also radically alter the state of glycosylation of the gut epithelium and thus further amplify their potent physiological effects. Accordingly, with the judicious use of dietary lectins it is now possible "to engineer' the digestive tract for improved physiological performance and bacterial ecology.
Pusztai
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Rowett Research Institute, Bucksburn, Aberdeen, Scotland, UK.
D000818:Animals; D002455:Cell Division; D005544:Forecasting; D006031:Glycosylation; D006801:Humans; D007413:Intestinal Mucosa / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D037102:Lectins / Q000494:pharmacology*
D037102:Lectins