Biological effects of plant lectins on the gastrointestinal tract: Metabolic consequences and applications

Abstract

Lectins are one of the most important physiologically active ingredients and potent exogeneous biological signals in the diet. Although the amounts of lectins in foodstuffs can vary considerably, they can dramatically affect the entire digestive tract and its bacterial population, body metabolism and health. Their extraordinary effectiveness stems from resistance to gut proteolysis and a high and specific chemical reactivity with endogenous surface receptors of the epithelial cells of the gut of both higher animals and lower organisms. Lectins are powerful oral and parenteral immunogens and some of their physiological effects are intricately linked to interference with immune function. However, the primary effects and the potency of lectins as biological signals are the direct result of their specific chemical reactivity with saccharides. As these reactions are predictable, the use of lectins as blockers of pathogens, immune stimulants, hormone modulators and metabolic agents in clinical-medical applications and as natural insecticides in transgenic plants, offers great promise.