The complexity of membrane-bound glycans in health and disease and the beneficial properties of glyconutrients

The surface of all free living cells and all multicellular cell types are covered with a dense and complex array of sugars mostly attached to proteins and lipids. These specific sugars are referred to as glycans and the biological role of these sugars includes cell-cell, cell-matrix, cell-molecule interactions, and interactions between other organisms. The chemistry of carbohydrates has been studied well since the first part of the 20th century without understanding the complexity of the glycans. The development of new technologies was the beginning for exploring a new field of molecular biology. Glycobiology is one of the more rapidly growing fields in natural science with a broad relevance to biotechnology, biomedicine and the nutritional supplement industry. Improved methods for analysis of these sugar structures are revealing remarkable complexity and diversity. While glycobiology contributes to the understanding of human health and disease, recent scientific research claims that certain plant extracts referred to as glyconutrients, can exert a wide range of effects on human health. Some plant-derived polysaccharides are among the best known and most potent immunomodulatory substances, impacting both humoral and cellular immune responses. Glyconutrient researchers imply a link between the research of prominent glycobiologists and the health benefits of glyconutrients. These actual or implied therapeutic claims have raised questions, some of which have been brought to the attention of glycobiologists. Glycobiologists claims that these plant polysaccharides are not digestible to monosaccharides by humans. Anaerobic bacteria in the colon can convert them to metabolic waste products such as butyric acid or other short-chain fatty acids, but not to monosaccharides available to the host. The question that arises is whether branched plant polysaccharides are effectively digested to provide biologically concentrations of individual monosaccharides that reach human tissue. On the other hand humans biosynthesize the different monosaccharides the body needs raising the question of whether dietary glycans are required. A wealth of findings suggests that there is a link between glycobiology and glyconutrients, and many publications support the conclusion that dietary glycans are key components in supporting optimal human health