2′-fucosyllactose: an abundant, genetically determined soluble glycan present in human milk

Abstract

Lactose is the preeminent soluble glycan in milk and a significant source of energy for most newborn mammals. Elongation of lactose with additional monosaccharides gives rise to a varied repertoire of free soluble glycans such as 2'-fucosyllactose (2'-FL), which is the most abundant oligosaccharide in human milk. In infants, 2'-FL is resistant to digestion and reaches the colon where it is partially fermented, behaving as soluble prebiotic fiber. Evidence also suggests that portions of small soluble milk glycans, including 2'-FL, are absorbed, thus raising the possibility of systemic biological effects. 2'-FL bears an epitope of the Secretor histo-blood group system; approximately 70-80% of all milk samples contain 2'-FL, since its synthesis depends on a fucosyltransferase that is not uniformly expressed. The fact that some infants are not exposed to 2'-FL has helped researchers to retrospectively probe for biological activities of this glycan. This review summarizes the attributes of 2'-FL in terms of its occurrence in mammalian phylogeny, its postulated biological activities, and its variability in human milk.

From Prediction to Function Using Evolutionary Genomics: Human-Specific Ecotypes of Lactobacillus reuteri Have Diverse Probiotic Functions

“…Propanediol is produced by gut microbes as a fermentation byproduct of rhamnose and fucose (Badia et al 1985). These simple sugars are components of glycoconjugates found in intestinal epithelial cells and plant cell walls (Bry et al 1996), as well as in breast milk oligosaccharides (Castanys-Munoz et al 2013). Sriramulu et al (2008) have shown that DSM 20016 (clade II) shows a growth advantage over rodent-derived L. reuteri 100-23 (that lacks the pdu – cbi – hem – cob cluster) when propanediol is provided in the growth medium, further supporting the idea that clade II strains preferentially utilize the propanediol dehydratase activity of PduCDE.…”

Dietary 2’-Fucosyllactose Enhances Operant Conditioning and Long-Term Potentiation via Gut-Brain Communication through the Vagus Nerve in Rodents

“…HMOs have been postulated as key ingredients for brain development due to their high abundance and variety in maternal milk when compared to bovine-milk based formulas [31]. Fucosylated HMOs are predominant in breast milk, especially 2’-FL which is the most abundant HMO, in most women’s milk [32]; while oligosaccharides from cow’s milk are mainly sialylated, and are present at low levels. Our group we reported the first in vivo study of dietary HMOs on CNS function, whereby 2´-FL potentiated LTP evoked at the hippocampus, improved learning and memory skills and impacted several brain markers of synaptic plasticity and brain function in rodents [17].…”

Effects of a human milk oligosaccharide, 2′-fucosyllactose, on hippocampal long-term potentiation and learning capabilities in rodents

“…HMOs have been postulated as key ingredients for brain development due to their high abundance and variety in maternal milk when compared to bovine-milk based formulas [37]. In particular, 2'-FL is the most abundant HMO in most women's milk [38], while oligosaccharides from cow's milk are mainly sialylated, and are present at low levels. Thus, dissecting a role for 2'-FL in cognitive development is of great interest.…”