Human Milk Oligosaccharides
Lactation Celebration Month and World Breastfeeding Week part 3….HMOs.
What are human milk oligosaccharides?
Human milk oligosaccharides, or HMOs, are carbohydrates. There are over 200 types of HMOs and your (super, duper awesome) body chooses the right combination for your baby’s age, immunological and environmental needs, and genetics. Our bodies also choose the HMOs based on the lactating parent’s nutritional status. HMOs are the 3rd most abundant solid ingredient in human milk…next to lactose and fat.
Why is their purpose?
Immunity
Feed our bifidobacteria (probiotics)
Anti inflammatory
Develop intestinal lining
How do HMOs affect my baby?
HMOs are pretty cool. Depending on your baby’s age and your environmental exposures, human milk contains anywhere from 5-15g of HMOs per liter. Because our bodies can’t digest HMOs, they reach the intestines intact where they get to work.
Immunity: HMOs can mimic the docking stations for bacteria and viruses so when they come along, they attach to HMOs instead of our bodies, thus preventing illness. They also block the bacteria and viruses from attaching to our bodies (check out my post on lactoferrin and iron to learn more about blocking and attaching to bacteria). HMOs also interfere with virus replication.
HMOs can be absorbed by our intestinal skin layer a tiny bit and can be found in other areas of our bodies but they are mainly found in the intestines, carrying bad bugs away and feeding good bugs.
Prebiotics: Because HMOs are not used for our nutrition, they are bountifully available as prebiotics (food for probiotics) for our bifidobacteria to munch on. Bifidobacteria are probiotics, or good bacteria, that live in our bodies. As bifidobacterial colonies grow, bad (pathogenic) bacterial colonies shrink. Yay!
Anti inflammatory: Certain HMOs have been shown to block pro-inflammatory chemicals (mediators) in the body. The exact mechanism is still being researched.
Gut maturation: Lastly, HMOs help set up an infant’s intestinal lining for optimal function. They coat the intestines and alter the microbiome to promote a healthy, balanced ecosystem.
Are HMOs available from other sources?
There are a few infant formulas that contain 1-2 strains of HMOs. 1-2 strains are better than 0 strains, but nothing can compare to the 200+ combinations of HMOs a lactating body can make!
What happens if we don’t have HMOs?
A lack of HMOs has been correlated to higher incidences of allergies, respiratory syncytial virus (RSV), norovirus, rotavirus, urogenital and airway infections, E.coli, enterocolitis, and Group-B strep (GBS). Because HMOs have been recently discovered, it has not been proven that they are the cause of lower incidences of these infections, however, researchers are taking note of trends.
References
Pediatric Gastroenterology, Hepatology & Nutrition, Immunological Effects of Human Milk Oligosaccharides, Diversity of Human Milk Oligosaccharides and Effects on Early Life Immune Development