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Polysaccharides are large sugar polymers made up of monosaccharide monomers such as glucose, galactose, fucose, fructose, mannose, xylose and arabinose. Glyconutritionals, also referred to as glyconutrients, are commercially inspired terms used to refer to especially formulated mixtures of special polysaccharides, such as exudate tree gums and high molecular weight aloe vera extracts, containing fermentable dietary fiber and plant extracts, as well as sugars or starch. "Glyconutrient" is a word that is sometimes used to refer to an individual carbohydrate nutrient.

Characteristics

The polysaccharide components have a significant degree of polymerization, often over 100, with the highest molecular weight polymers well over 1,0000,000 daltons. Some glyconutrient formulas may contain an individual sugar (e.g. glucosamine) or starch either as a functional food or filler. Other minor content such as minerals, protein and peptides may be present from the natural sources. The polysaccharides in glyconutrient formulas typically have higher molecular weight components, monosaccharide structural units less common in prebiotics, and, possibly, additional mechanisms of action over typical prebiotics containing shorter oligosaccharides.

Use as alternative therapy

A number of companies and individuals attempt to empirically optimize formulas for cost and perceived performance. Components of various mixtures have included high molecular weight extracts from aloe vera, high molecular weight arabinogalactan fraction of Larch extract, gum arabic (gum acacia), gum ghatti, gum tragacanth, oat fiber, fenugreek seed, kelp, Shiitake mushroom, psyllium husk, bovine cartilage powder and glucosamine. Different formula compositions should be expected to have different effects that vary by individual and condition. Many of these components have long been used in food processing and health remedies.

Nutritional and medical sciences have long noted soluble fiber, including polysaccharides, as largely undigested in the small intestine. The soluble fibers are then fermented in the colon into highly beneficial short chain fatty acids, butyrate being especially beneficial. Anti-inflamatory benefits are associated with several glyconutrients including gum acacia and glucosamine. Current research supports benefits and mechanisms such as increased beneficial bacteria (e.g. bifidus, lactobacillus) - a prebiotic effect, a decrease in opportunistic pathogens, immune activation and stimulation, increased efficiency of digestion and absorption of nutrients, decreased circulating free fatty acids that cause cellular insulin resistance, decreased luminal ammonia concentration. Many benefits of these substances are not duplicated by other nutrients, vitamins, minerals, fats and amino acids.

Amounts advertised as minumum vendor recommendations, apparently for healthy customers, are sometimes substantially lower than actual daily usage amounts reported by other customers as necessary to achieve satisfaction, often by a factor of 8 to 25. Amounts consumed typically depend upon individual perception of requirements for improvement, product cost, financial constraints, formulation and physiological limitations on fiber load. Self mixers report 70%-85% savings for high cost commercial formulations. In the US, during 2005, retail costs of typical "glyconutrient" formulations ranged from about $14, self mixed, to over $500 per pound ($30 - $1200+/kg) depending on source(s), quantity, and components.

Prebiotics, with a lower degree of polymerization, available under $8/lb for some mail order inulin sources, are used both as complementary and as alternative materials to glyconutrient formulas.

Controversy; relation to glycobiology

For some sources of these formulas, sensationalism, conflated scientific ideas and controversial marketing methods abound. Some purchasers rely soley on sales representations rather than including advice from knowledgeable, independent, health care professionals, an approach generally considered "at risk". Substantial supplementation with any dietary formula is generally recommended as a part of a comprehensive nutritional, medical or health plan, not a replacement for one.

Many claims of uses, benefits and scientific theories are encountered by the public in various media, but the specific benefits and mechanisms of glyconutrients are debated. Some promoters of glyconutritional formulas espouse a popularized view that the polysaccharide components are capable of being materially hydrolyzed and absorbed as monosaccharides for beneficial use in human cells. Based on this unsubstantiated claim of digestion as monosaccharides and the popularized notion of "8 essential sugars (monosaccharides)", they further promote physiological connections, broadly not accepted, to the established science of glycobiology as well as cellular phenomena such as glycosylation and formation of glycoproteins. These popularized notions have little support in science and medicine and have no significantly documented basis. They are not in accord with the traditional scientific discipline of glycobiology, which attempts to study the roles of saccharides in biology from a descriptive, rather than a treatment-oriented perspective.

Nevertheless some "glyconutrients" have been associated with health remedies, various forms of medicine, special foodstuffs, and food additives for centuries and even millenia, across cultures, up to the present day.

References

• Martin Peterson, Arnold Johnson (1978) Encyclopedia of Food Science, Avi Publishing Co., Westport CT ISBN 0870552279
• Coates MD, et al. Molecular defects in mucosal serotonin content and decreased serotonin reuptake transporter in ulcerative colitis and irritable bowel syndrome. Gastroenterology. 2004 Jun;126(7):1657-64.
• Kotarsky K, et al, Progress in methodology. Improved reporter gene assays used to identify ligands acting on orphan seven-transmembrane receptors. Pharmacol Toxicol. 2003 Dec;93(6):249-58. Review.
• Nilsson NE. Identification of a free fatty acid receptor, FFA2R, expressed on leukocytes and activated by short-chain fatty acids. Biochem Biophys Res Commun. 2003 Apr 18;303(4):1047-52.
• Kida Y, Sodium butyrate up-regulates cathelicidin gene expression via activator protein-1 and histone acetylation at the promoter region in a human lung epithelial cell line, EBC-1. Mol Immunol. 2006 Jan 16
• De Smet K, Contreras R., Human antimicrobial peptides: defensins, cathelicidins and histatins. Biotechnol Lett. 2005 Sep;27(18):1337-47. Review.
• AND Zanetti M. The role of cathelicidins in the innate host defenses of mammals. Curr Issues Mol Biol. 2005 Jul;7(2):179-96. Review.
• Lopez-Garcia B, et al. Anti-fungal activity of cathelicidins and their potential role in Candida albicans skin infection. J Invest Dermatol. 2005 Jul;125(1):108-15.
• Matsumoto N, Riley S, Fraser D, Al-Assaf S, Ishimura E, Wolever T, Phillips GO, Phillips AO. Butyrate modulates TGF-beta1 generation and function: Potential renal benefit for Acacia(sen) SUPERGUM (gum arabic)? Kidney Int. 2006 Feb;69(2):257-65.
• Ying M, Xu R, Wu X, Zhu H, Zhuang Y, Han M, Xu T. Sodium butyrate ameliorates histone hypoacetylation and neurodegenerative phenotypes in a mouse model for DRPLA.J Biol Chem. 2005 Dec 28.
• Entin-Meer M, Rephaeli A, Yang X, Nudelman A, VandenBerg SR, Haas-Kogan DA. Butyric acid prodrugs are histone deacetylase inhibitors that show antineoplastic activity and radiosensitizing capacity in the treatment of malignant gliomas. Mol Cancer Ther. 2005 Dec;4(12):1952-61.
• Yusta B, Ortiz-Caro J, Pascual A, Aranda A. Mechanism of L-triiodothyronine (T3) uptake by glial C6 cells: regulation by butyrate. Mol Cell Endocrinol. 1988 Aug;58(2-3):191-8.
• Kida Y, Shimizu T, Kuwano K. Links Sodium butyrate up-regulates cathelicidin gene expression via activator protein-1 and histone acetylation at the promoter region in a human lung epithelial cell line, EBC-1. Mol Immunol. 2006 Jan 16;
• Soderberg LS, Boger S, Fifer EK, Gilbert KM. Macrophage production of inflammatory mediators is potently inhibited by a butyric acid derivative demonstrated to inactivate antigen-stimulated T cells. Int Immunopharmacol. 2004 Sep;4(9):1231-9.
• Gupta SK, Pillarisetti K, Aiyar N. CXCR4 undergoes complex lineage and inducing agent-dependent dissociation of expression and functional responsiveness to SDF-1alpha during myeloid differentiation. J Leukoc Biol. 2001 Sep;70(3):431-8.
• Shibuta K, Mori M, Shimoda K, Inoue H, Mitra P, Barnard GF. Regional expression of CXCL12/CXCR4 in liver and hepatocellular carcinoma and cell-cycle variation during in vitro differentiation.Jpn J Cancer Res. 2002 Jul;93(7):789-97.
• Jordan NJ, Kolios G, Abbot SE, Sinai MA, Thompson DA, Petraki K, Westwick J. Expression of functional CXCR4 chemokine receptors on human colonic epithelial cells. J Clin Invest. 1999 Oct;104(8):1061-9.

External links

• - Fermentation of polysaccharides by Klebsielleae and other facultative bacilli
• - "The New Vision" Uganda newspaper's coverage on Glyconutrients and HIV
• - Glycoscience.org: MannaTech publications on glyconutrients
• - An unfavorable, critical look at nutrient-based therapies in general

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