Goat Milk Oligosaccharides: Their Diversity, Quantity, and Functional Properties in Comparison to Human Milk Oligosaccharides

Abstract

Human milk is considered the golden standard in infant nutrition. Free oligosaccharides in human milk provide important health benefits. These oligosaccharides function as prebiotics, immune modulators, and pathogen inhibitors and were found to improve barrier function in the gut. Infant formulas nowadays often contain prebiotics but lack the specific functions of human milk oligosaccharides (hMOS). Milk from domesticated animals also contains milk oligosaccharides but at much lower levels and with less diversity. Goat milk contains significantly more oligosaccharides (gMOS) than bovine (bMOS) or sheep (sMOS) milk and also has a larger diversity of structures. This review summarizes structural studies, revealing a diversity of up to 77 annotated gMOS structures with almost 40 structures fully characterized. Quantitative studies of goat milk oligosaccharides range from 60 to 350 mg/L in mature milk and from 200 to 650 mg/L in colostrum. These levels are clearly lower than in human milk (5–20 g/L) but higher than in other domesticated dairy animals, e.g., bovine (30–60 mg/L) and sheep (20–40 mg/L). Finally, the review focuses on demonstrated and potential functionalities of gMOS. Some studies have shown anti-inflammatory effects of mixtures enriched in gMOS. Goat MOS also display prebiotic potential, particularly in stimulating growth of bifidobacteria preferentially. Although functional studies of gMOS are still limited, several structures are also found in human milk and have known functions as immune modulators and pathogen inhibitors. In conclusion, goat milk constitutes a promising alternative source for milk oligosaccharides, which can be used in infant formula.

Traditional Bulgarian Dairy Products: Ethnic Foods with Health Benefits

“…MO are even more heterogeneous and are composed of five monosaccharides: D-glucose, D-galactose, N-acetylglucosamine, L-fucose, and sialic acid (N-acetylneuraminic acid) [105]. A brand-new study by van Leeuwen et al (2020) ranks goat's milk products as the richest in MO, ranging from 60 to 350 mg/L, considerably more than those from bovine (30-60 mg/L) and sheep's milk (20-40 mg/L) [106]. Both GOS and MO stimulate the growth of bifidobacteria, especially of Bifidobacterium longum subsp.…”

Extraction and Quantitative Analysis of Goat Milk Oligosaccharides: Composition, Variation, Associations, and 2′-FL Variability

“…Finally, some gMOS studies focus only on specific structures (i.e., 3′-, 6′-sialyllactose and disialyllactose 23 ), not facilitating the understanding of the complete gMOS “fingerprint”. 24 …”

Current Perspective of Sialylated Milk Oligosaccharides in Mammalian Milk: Implications for Brain and Gut Health of Newborns

“…Caprine milk offers yet another potential alternative to human milk, due to the enhanced digestibility of goat milk compared to cow milk [ 67 ]. Goat milk is reported to be closer to human milk than bovine milk in regard to the protein, fatty acid, and casein content and structure of casein [ 68 ] and oligosaccharides [ 69 ]. The concentration of goat milk oligosaccharides is about 0.20–0.65 g/L in colostrum and 0.06–0.35 g/L in mature milk [ 69 ].…”

“…Goat milk is reported to be closer to human milk than bovine milk in regard to the protein, fatty acid, and casein content and structure of casein [ 68 ] and oligosaccharides [ 69 ]. The concentration of goat milk oligosaccharides is about 0.20–0.65 g/L in colostrum and 0.06–0.35 g/L in mature milk [ 69 ]. A total of 78 different structures of oligosaccharides have been characterized in caprine colostrum, with approximately 45% of these oligosaccharides being sialylated [ 70 ].…”