Breast Milk Component Boosts Infant Brain Connectivity

Summary: Researchers have discovered that myo-inositol, a small cyclic sugar molecule found in breast milk, plays a crucial role in promoting neuronal connections in infants’ brains.

Prior studies indicated the cognitive benefits of breast milk but were unclear about the specific components responsible. Myo-inositol was identified in high concentrations in breast milk samples from diverse geographic locations, decreasing over the course of lactation.

This groundbreaking research underscores the importance of breastfeeding in infants’ cognitive development and informs future dietary recommendations.

Key Facts:

  1. Myo-inositol, a component of breast milk, has been identified as a crucial promoter of neuronal connections in infant brains.
  2. The presence of myo-inositol is high in early lactation, gradually diminishing over time, and is independent of the mother’s diet, race, and location.
  3. This study underscores the significance of breastfeeding in the cognitive development of infants, and highlights the importance of policies supporting breastfeeding mothers.

Source: Yale

Breast milk is not simply sustenance. It also is rich in micronutrients that are critical for healthy brain development in infants.

Now, researchers have identified a component of breast milk that promotes how neurons form connections in infants’ brains. Myo-inositol is a small cyclic sugar molecule in breast milk that also is found in a typical adult diet, including in fruits and grains. The study emphasizes the powerful role that what we eat plays in brain function.

It was published in PNAS on July 11.

This shows a happy baby.
The current study focuses on the production of connections in the brain, a hallmark of the first months after birth. Credit: Neuroscience News

“The effects of micronutrients on the brain are really under-appreciated,” says Thomas Biederer, Ph.D., associate professor of neurology and principal investigator. “As a neuroscientist, our findings were stunning to me.”

Prior studies have demonstrated that breast milk is beneficial for the cognitive development of infants, but researchers had little understanding of why. Some proposed that breast milk contains certain unidentified components that provide these benefits.

“Breast milk is rich in bioactive compounds that we are only starting to understand,” says Biederer. “The infant brain is using those compounds to support its developmental processes.”

The starting point of this study was a lead provided by the Biederer lab’s partners at Mead Johnson Nutrition/Reckitt who did a detailed analysis of milk samples donated by mothers at sites in Cincinnati, Mexico City, and Shanghai over the course of lactation.

The researchers wanted to study samples from three geographically diverse locations because they hypothesized that the micronutrients present across all samples—independent of diet, race, and location—may be of biological significance.

They were especially interested in components that changed over the course of lactation in the same way.

The team noticed that myo-inositol was present in all breast milk samples in high concentrations early on, and gradually diminished over the course of lactation. Importantly, it also had an identical temporal profile across all three sites. “The molecule is very robustly controlled by the mother,” says Biederer.

Intrigued, they examined the effects of myo-inositol on the developing brain using a variety of models, including cultured human neurons and cultured brain tissue. They found that the sugar molecule boosted synapse abundance in the neurons and enhanced neuronal connectivity.

“Our study demonstrates that breast milk is extremely valuable in how mothers can support the formation of connections in an infant’s brain,” says Biederer.

“It truly shows the importance of valuing the complexity of breast milk. It’s not just a source of calories, but an extremely rich, complex biofluid, and the mother’s body is really attuned to changing the composition of breast milk to match what the infant needs at different stages of development.”

These results can guide dietary recommendations for pediatric nutrition. The findings also emphasize the importance of having policies that support breast feeding mothers, says Biederer, because these policies “will help benefit society as a whole.”

The current study focuses on the production of connections in the brain, a hallmark of the first months after birth. After these connections are established, the brain then works to refine and optimize these connections.

In future studies, Biederer would like to explore how breast milk supports infants during this later stage of development.

“Refinement is a critical process for creating the right patterns in the brain,” says Biederer. “Studying this stage will be as important, if not more important, than studying the initial formation of connections.”

About this breastfeeding and neurodevelopment research news

Author: Isabella Backman
Source: Yale
Contact: Isabella Backman – Yale
Image: The image is credited to Neuroscience News

Original Research: Open access.
The human milk component myo -inositol promotes neuronal connectivity” by Andrew F. Paquette et al. PNAS


The human milk component myo -inositol promotes neuronal connectivity

Effects of micronutrients on brain connectivity are incompletely understood. Analyzing human milk samples across global populations, we identified the carbocyclic sugar myo-inositol as a component that promotes brain development.

We determined that it is most abundant in human milk during early lactation when neuronal connections rapidly form in the infant brain. 

Myo-inositol promoted synapse abundance in human excitatory neurons as well as cultured rat neurons and acted in a dose-dependent manner. Mechanistically, myo-inositol enhanced the ability of neurons to respond to transsynaptic interactions that induce synapses.

Effects of myo-inositol in the developing brain were tested in mice, and its dietary supplementation enlarged excitatory postsynaptic sites in the maturing cortex.

Utilizing an organotypic slice culture system, we additionally determined that myo-inositol is bioactive in mature brain tissue, and treatment of organotypic slices with this carbocyclic sugar increased the number and size of postsynaptic specializations and excitatory synapse density.

This study advances our understanding of the impact of human milk on the infant brain and identifies myo-inositol as a breast milk component that promotes the formation of neuronal connections.

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  1. Hi, from Europe!
    To Abir… Your Baby will teach you. Don’t worry. As far as I understood the Suret (233) thank you for sharing the translation! It is an advice to have a clue.
    I am not a mother, but with Babies I have a 6th sense. I do not know why. All I know is from the first day on this fascinating planet (or even before!) they have an own ‘will’ or better expressed ‘instinct’.
    Kind regards
    PS:I like the expression ‘with my respect’ I never read it before…

  2. There needs to be one more piece of critical research done, the physical and emotional presence of the mother—the inositol and other micro-nutrients in breastmilk, combined with the physical touch and emotional interaction with the mother provides the greatest value. Adding inositol to formula and propping a bottle up for a baby in a crib will not yield the same result.

  3. “Breast Milk Component Boosts Infant Brain Connectivity“

    Let me correct this for you: Breastmilk provides components for brain connectivity development.

    Breastfeeding is the baseline, it contains all the elements needed for healthy, optimal growth. Artificial feeding is the deviation from the biological norm, and doesn’t contain these micronutrients, meaning babies that are not breastfed are not developing normally.

  4. Dear Scientist,

    As a mother for the first time, I am reading the article happily as I choose to breastfeed my 9 months baby and I an intending to continue breast feeding till she reaches 2 years ( I pray for Almighty Allah to help me). In our Holy Quran there is a verse (233) in Suret al Baqra that recommends the women to breastfeed her baby for two years…it is written below …

    “Mothers may breastfeed their children two complete years for whoever wishes to complete the nursing [period]. Upon the father is the mothers\’ provision and their clothing according to what is acceptable. No person is charged with more than his capacity. No mother should be harmed through her child, and no father through his child. And upon the [father\’s] heir is [a duty] like that [of the father]. And if they both desire weaning through mutual consent from both of them and consultation, there is no blame upon either of them. And if you wish to have your children nursed by a substitute, there is no blame upon you as long as you give payment according to what is acceptable. And fear Allah and know that Allah is Seeing of what you do. (233)”

    from science point of view why do you think two years is the optimum period for breastfeeding? Is is this duration reflected positively on mother also as well as on baby?

    With my respect,

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