Oligosaccharides in Milk: Their Benefits and Future Utilization

Abstract

The percentage of carbohydrate in the milk/colostrum of the mammalian is range from trace to over 10%, of which disaccharide lactose (Gal(β1-4)Glc) is usually constitutes the major part. Apart from the lactose (Gal(β1-4)Glc; Gal, D-galactose; Glc, D-glucose), the rest of carbohydrate components is composed of variety of sugars, commonly named as milk oligosaccharides. Human mature milk and colostrum contain 12 ~ 13 g/l and 22 ~ 24 g/l of oligosaccharides, respectively. In contrast, bovine colostrum contains more than 1 g/l oligosaccharides and this concentration rapidly decreases after 48 hr post partum. Most of human milk oligosaccharides (HMO) are resistant to digestion and absorption within the small intestine. Therefore they can reach the infant colon, where they can act as prebiotics that stimulate the growth of benefi cial microorganisms such as various species of Bifi dobacterium. They can also act as receptor analogues that inhibit the a achment of pathogenic microorganisms to the infant's colonic mucosa. A small part of the milk oligosaccharides is absorbed intact into the circulation and it has been hypothesized that these may act as immunomodulators. Generally, the bovine milk oligosaccharides are believed not to be absorbed by human adults or infants, thus making them available to be utilized as prebiotics or anti-infection materials. The colostrum of cows and other domestic farm animals is a potential source of free oligosaccharides, and oligosaccharides isolated from these natural sources can be utilized as functional foods or animal feedstuff s on the industrial scale.Key words: milk, oligosaccharides, prebiotic, Bifi dobacterium * Corresponding author: e-mail: urashima@obihiro.ac.jp oligosaccharides . In this review, we will introduce the structural feature of human milk oligosaccharides, on their fate within the gastrointestinal tract as well as on their possible biological functions as prebiotics, anti infection agents and immunomodulation factors. In addition, we will discuss the possibility of the commercial utilization of bovine milk oligosaccharides and those of other domestic farm animals. THE CHEMICAL STRUCTURES AND THEIR QUANTITATIVE ASPECTS OF HUMAN MILK OLIGOSACCHARIDESThe structures of at least 115 human milk oligosaccharides (HMOs) have been determined to date (Urashima et al., in press), while as many as 200 diff erent oligosaccharides have been separated and studied by microfl uidic high performance liquid chromatography

Oligosaccharide concentrations in colostrum, transition milk, and mature milk of primi- and multiparous Holstein cows during the first week of lactation

“…In addition, a direct comparison between these 2 species is unwarranted due to differences in genetics, production, and nutrition. Although little is known about how parity number in bovine animals may affect OS concentration and yield, OS synthesis in the mammary gland is known to occur by the action of a glycosyltransferase (e.g., sialyltransferase) specific to each molecule (Urashima and Taufik, 2011), which takes place in different compartments of the cell, including the cytosol, nucleus, and Golgi apparatus (Wickramasinghe et al, 2011;Petrosyan et al, 2012). Wickramasinghe et al (2011) demonstrated that 92 glycosylated-related genes were involved in OS metabolism pathways in bovine somatic cells, which are representative of mammary gland tissue (Cánovas et al, 2014), at d 15 and 250 of lactation.…”

Oligosaccharides in goats’ milk-based infant formula and their prebiotic and anti-infection properties

“…Cows' milk-based infant formulas are widely used, but goats' milk-based products are becoming increasingly popular as goats' milk is considered to be more similar to human milk compared with cows' milk. This includes higher levels of oligosaccharides in goats' milk relative to milk of other mammalian species (2) and lower levels of α-S1 casein (3) . Goats' milk is also reported to exhibit significant homology in lactoferrin N-glycans with human milk (4) .…”

Bio‐therapeutics from human milk: prospects and perspectives

“…Quite frequently lactose is attached with sialic acid residues to form trisaccharides also called as short‐chain milk oligosaccharides. Sialyted lactose could be extended by more N ‐acetylglucosamine repeats up to as long as 15 residues to form complex oligosaccharides (Urashima and Taufik 2010).…”