An oligosaccharide is a saccharide polymer containing a small number (typically three to six) of component sugars, also known as simple sugars. They are generally found either O- or N-linked to compatible amino acid side chains in proteins or to lipid moieties.
Oligosaccharides are often found as a component of glycoproteins or glycolipids and as such are often used as chemical markers, often for cell recognition. An example is ABO blood type specificity. A and B blood types have two different oligosaccharide glycolipids embedded in the cell membranes of the red blood cells, AB-type blood has both, while O blood type has none.
Not all natural oligosaccharides occur as components of glycoproteins or glycolipids. Some, such as the raffinose series, occur as storage or transport carbohydrates in plants. Others, such as maltodextrins or cellodextrins, result from the microbial breakdown of larger polysaccharides such as starch or cellulose.
Human polymorphism, oligosaccharides and lactation variation
Do the binding properties of oligosaccharides in milk protect human infants from gastrointestinal bacteria?
Newburg DS J Nutr 1997 May;127(5 Suppl):980S-984S Department of Biochemistry, Shriver Center for Mental Retardation, Waltham, MA 02254, USA.
- The oligosaccharide fraction of human milk, the third most abundant solid constituent, consists of hundreds of structures, many of them fucosylated. Oligosaccharides may bear structural homology to cell surface glycoconjugates used as receptors by pathogens, thus protecting nursing infants. The ability of human milk to protect against heat-stable enterotoxin of Escherichia coli in suckling mice has been attributed to neutral fucosylated oligosaccharides of milk. Because Campylobacter binds H-2 type oligosaccharide structures, the concentration of protective oligosaccharide may also be inferred from the total oligosaccharide profile. The relationship between oligosaccharide profile heterogeneity in human milk and the incidence of specific gastrointestinal bacterial disease in infants consuming these milks could indicate the significance of these oligosaccharides to infant health. The efficacy of synthetic analogs of active oligosaccharides will confirm their clinical relevance and define minimum structural features essential for activity.
Variations of lactose and oligosaccharides in milk from women of blood types secretor A or H, secretor Lewis, and secretor H/nonsecretor Lewis during the course of lactation
Viverge D, Grimmonprez L, Cassanas G, Bardet L, Bonnet H, Solere M 1985;29(1):1-11
- Variations of lactose and oligosaccharides in human milk were studied over a 3-month lactation period by dialysis, chromatography on Bio-gel P-2 column, paper chromatography, colorimetric analysis and gas chromatography. Milk samples were collected from donors of various blood and secretor types. An increase in the concentration of lactose was noted: 59.25 +/- 1.61 to 72.17 +/- 1.35 g/l for the group of secretor A secretor Lea Leb individuals, and from 62.25 +/- 1.35 to 73.15 +/- 3.45 g/l for the group of secretor H secretor Lea Leb individuals. A decrease in the concentration of oligosaccharides was also found: from 16.71 +/- 0.99 to 7.90 +/- 1.29 g/l and from 18.51 +/- 0.74 to 7.33 +/- 0.65 g/l, respectively, for these same groups. In secretor H nonsecretor Lewis individuals, the concentration of lactose increased from 67.97 +/- 3.09 to 77.42 +/- 1.88 g/l, and the concentration of oligosaccharides decreased from 13.27 +/- 0.40 to 3.47 +/- 0.33 g/l. Analysis of oligosaccharide composition by chromatography showed that variations are in relation to the secretor Lewis type. All oligosaccharides decreased equally throughout the lactation period, regardless of the blood group. The decrease was more rapid, however, in the nonsecretor Lewis individuals.