I love all things breastfeeding. Well, almost all things. Sans the biting, mastitis, clogged ducts, and the painfully engorged boobs…

There are a lot of amazing things about breastmilk. Like how it contains antibodies to protect baby while their immune system is still developing. And how breastmilk composition changes during a breastfeeding session, throughout the day and during the first year.

But my very favorite thing about breastmilk is HMOs. If you haven’t heard about HMOs, you aren’t alone. OBs, midwives, and pediatricians aren’t teaching moms about them and why they are so special.

So sit tight, because today you’re going to learn about these amazing sugars in your breastmilk!

HMOs are Human Milk Oligosaccharides. After lipids and lactose, HMOs are the 3rd most abundant component of breastmilk (yes, there are more HMOs in breastmilk than protein!)

But what are they exactly?

HMOs are complex sugars in human milk that have chemical bonds that your baby’s enzymes can’t break. Only certain bacteria (like Bifidobacterium) possess the enzymes needed to break the chemical bonds of HMOs and access the sugar for energy.

Why does this matter? And why are HMO sugars even in breastmilk if baby can’t use them for energy and growth?

HMOs are in breastmilk solely to feed Bifidobacterium! Bifido loves HMOs! And it feasts every time a baby is breastfed. The well-fed Bifido then divide and multiply and take up a lot of microbiome real-estate so that other bacteria and pathogens have less room to grow.

During the first 4-6 months of life early months, at least 80% of baby’s gut microbiome should be Bifidobacterium. This helps their gut microbiome and immune system to develop properly. Babies with microbiomes that are dominated by other species during the first few months are more likely to develop diseases like asthma, obesity and atopic dermatitis.

Long story short, HMOs and Bifidobacterium are the keys to a healthy infant gut.

If you are unable to breastfeed for whatever reason, don’t fret! Choose a formula that contains HMOs, like 2’-FL and LNnT. Although there are fewer HMOs in formula than in breastmilk, any amount of HMOs are beneficial and will help keep bifido levels up.

HMOs are my favorite thing about breastmilk.

But my favorite thing about breastfeeding has to be the latched smiles. Oh my heart!!!

References:

Dinleyici M, Barbieur J, Dinleyici EC, Vandenplas Y. Functional effects of human milk oligosaccharides (HMOs). Gut Microbes. 2023 Jan-Dec;15(1):2186115. doi: 10.1080/19490976.2023.2186115. PMID: 36929926; PMCID: PMC10026937.

Mathuaru, Dollwin et al. Human milk oligosaccharide composition is affected by season and parity and associates with infant gut microbiota in a birth mode dependent manner in a Finnish birth cohort. Volume 104, 105182