Human Milk Oligosaccharides (HMOs)

Human milk oligosaccharides (HMOs) are structurally similar to mucin O-glycans, naturally occurring in human milk and are the third largest solid component of human milk, after lactose and lipids
Zhang et al. 2021 Microb Cell Fact 20(1): 108
Luis & Hansson 2023 Cell Host & Microbe 31(7):

They are synthesized in the Mammary gland
Ishiguro et al. 2023 Academic Press ISBN 978-0-323-91387-4

Maternal genomic variants in the fucosyltransferase 2 (FUT2) and Fatty acid desaturase (FADS) genes are linked to human milk oligosaccharides (HMOs) and fatty acids, respectively.
Miliku et al. 2019 Am. J. Clin. Nutr. 110: 1370-1383
Williams et al. 2021 Genomics 113: 1867-1875

Oligosaccharides from human milk (HMOs) or bovine milk selectively stimulate the growth and metabolism of bacteria associated with the lower gastrointestinal tract of infants.
Jakobsen et al. 2020 Metabolites 10: 167

Human Milk Oligosaccharides (HMOs) are complex glycans comprising glucose, galactose, fucose, sialic acid, and N-acetylglucosamine, collectively making up the third most abundant component of breast milk
Bode 2015 Early Hum. Dev. 91: 619–622

Structural classification of HMOs (Abbreviations: 2′FL = 2′-Fucosyllactose (2’FL), 3′FL = 3′-Fucosyllactose, LNnT = Lacto-N-neotetraose, LNT= lacto-N-tetraose, 3′SL= 3′-Sialyllactose, 6′SL = 6′-Sialyllactose
Bode 2015 Early Hum. Dev. 91: 619–622

Over 200 structurally distinct HMOs have been identified to date, broadly categorized into three structural groups
Ruhaak & Lebrilla 2012 Adv. Nutr. 3: 406S–414S

Not every woman exhibits the same pattern of Human Milk Oligosaccharides (HMOs), as their synthesis shows interindividual variation, depending on different possible genotypes
Thurl et al. 2010 Br. J. Nutr. 104: 1261–1271

Some Commensal Bacteria / Commensalism evolved to utilize HMOs and O-glycans as a carbon source.
Luis & Hansson 2023 Cell Host & Microbe 31(7):

Human Milk Oligosaccharides (HMOs) benefits for infants are:

• activity as antivirals and Antimicrobials / Antimicrobial activity


• activity as prebiotic, selectively enhancing the growth of bifidobacteria


• production of SCFAs


• interaction with immune cells to affect the expression of pro-inflammatory or Anti-inflammatory cytokines

Walsh et al. 2020a J Funct Foods 72: 104074

Furthermore, they can program the immune system and reduce the incidence of allergies and autoimmune diseases
Doherty et al. 2018b Front. Pediatr. 6: 91
Bode 2020 Nestle Nutr. Inst. Workshop Ser. 94: 1–9

They serve not only as prebiotics, but they exert a protective role against some significant neonatal pathologies such as necrotizing enterocolitis. They also act as anti-adhesive and antimicrobial factors
Craft & Townsend 2019 Acc. Chem. Res. 52: 760–768

HMOs also play a crucial role in brain development and the gut barrier’s maturation
Mudd et al. 2017 Nutrients 9: 1297

2′-Fucosyllactose (2’FL) and Lacto-N-neotetraose are currently approved in supplemented formulas
Sprenger et al. 2017 J. Biotechnol. 258: 79–91

see also:
Bifidobacterium longum infantis EVC001
Breastfeeding
Childhood / Child & Development of Gut Microbiota
Digestion & O-Glycans / O-Linked Glycosylation
Human milk / Breast milk