I love milk. Billions of people drink milk every day.
Milk naturally contains infection-fighting properties. Commercial baby formula usually does not. Funding from USDA’s National Institute of Food and Agriculture and other sponsors allowed me to explore an element of milk that could be used as a supplement in baby formula to boost nutrition and stave off infection. This same element can help balance your gut bacteria when you take antibiotics.
If I asked you about the nutritional importance of milk, nutrients such as calcium and vitamin D might come to mind. But there’s more. I began exploring novel bioactive compounds in cow’s milk in 2014 and discovered that milk contains around 6 trillion natural nanoparticles called “exosomes,” per fluid ounce. When you drink milk, milk exosomes enter your body and deliver a variety of proteins, lipids, RNA and DNA to the liver, brain, placenta and the gut. Upon reaching these tissues, exosomes and their cargos work their magic and support essential functions such as learning and memory, the immune system and reproduction. Not all exosomes ingested with milk find their way into human tissues. Some stay in your gut and interact with bacteria in an environment called a “microbiome.”
My research involved studying exosome-microbiome interactions in milk. My findings suggest that milk exosomes alter the genetic makeup of bacteria. For example, what used to be a fairly quiet bacteria might turn more virulent in the absence of milk exosomes. In a related line of research, I showed that dietary depletion of milk exosomes shortened the life span of mice challenged with influenza A virus compared with mice fed a milk exosome-sufficient diet.
How can this discovery about milk exosomes be translated into a healthier nutrition to benefit society? First, while pediatricians recommend exclusive breastfeeding in the first six months of life, most babies (for a variety of reasons) are fed infant formula. Commercial formula contains little, if any, exosomes. Supplementing formula with milk exosomes can make it more like human milk. This is of particular importance for premature infants, who are predisposed to developing gastrointestinal diseases. Infants in developing countries may also benefit from supplemented formula, because they often receive formula in the first stages of life, and then solid foods introduced at weaning may be of low quality. Second, many gut pathogens have developed a resistance to antibiotics, and a healthy diet including milk exosomes may help keep undesirable bacteria in check.
The natural infection fighting properties contained in milk, either through breast milk or possibly through formula supplements, could mean a better start to life for infants worldwide.
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