12/19/2025
😮❤️
Human milk is not static. It responds to the environment, including the season!!! 😮
A 2024 study published in eBioMedicine found that the types and amounts of human milk oligosaccharides change depending on the time of year (Matharu et al., 2024). HMOs are complex sugars in breast milk that do not feed the baby directly. Instead, they nourish beneficial gut bacteria and play a key role in shaping immune development 🦠🛡️
The researchers observed that during colder months, when respiratory and gastrointestinal infections are MORE prevalent, specific HMOs were present in different concentrations and patterns. These seasonal changes in milk composition were associated with measurable differences in the infant gut microbiota… meaning the bacteria living in the baby’s intestines shifted alongside the milk they received 🧬🫨
SOOOO why does this matter to us?
HMOs *promote* the growth of protective bacteria while helping block pathogens from attaching to the gut lining. Seasonal adjustments in HMOs may help infants better adapt to seasonal infection, particularly during winter when illness risk is higher ❄️🤍
In simple terms: your breast milk is season aware. It adjusts to help protect your baby when winter bugs are circulating and supports gut and immune health in ways that CANNOT be replicated by formula.
