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Mamas, YOUR Microbes May Affect Your Children’s Health

Jennifer Margulis, Ph.D.

Riddle us this: Two girls—best friends—grow up in the same small town, go to the same school, and have similar diets, lifestyle practices, and even extracurricular activities.

Both of their moms are committed to feeding their daughters organically-grown whole, real, healthy foods; making sure they get lots of time outside to play in the dirt and soak up the sun; and having a set bedtime so they each get enough sleep.

One girl is healthy as a horse—so healthy, in fact, that she rarely gets sick, has never taken an antibiotic, and never missed a single day of school. But the other girl is plagued with health problems, including high fevers and intractable skin rashes that bother her for months at a time. She seems to bring every bug going around home and she often misses school because she’s too sick to attend.

This is a hippie town on the West Coast and neither child is vaccinated. So, not surprisingly, both girls ended up getting chickenpox. The girl who is often sick was bed-bound with a high fever, large pox that oozed and blistered, and lethargy. Her glands got swollen and she barely had the energy to sit up in bed. But the girl who rarely gets sick, on the other hand, had no fever and only a smattering of pox. She was so energetic, in fact, that she begged her father to take her to the skate park.

This is a true story. One that has long puzzled us.

Given their similarities, why was one friend sick all the time and the other so healthy?

It would be easy to say that it’s “in their genes” or to blame stress (the sick child’s parents divorced when she was little and continue to have an antagonistic relationship and a growing body of research shows that stress suppresses the immune system and can literally make you sick).

But now a new peer-reviewed study, published in the journal Cell, suggests another explanation: the sick child’s mother’s microbiome may be partially to blame for her daughter’s ongoing health struggles.

Microbes in a Mother’s Gut Transfer Genes to Her Baby

As detailed in this new study, researchers discovered that the microbes in a mother’s gut can transfer genes directly to their infant’s gut microbes. They do this without transferring the whole strains of microbes from mother to child.

This work was done by a team at the Broad Institute of MIT and Harvard.

The Broad Institute is a non-profit research center in Cambridge, Massachusetts that is focused on genomic medicine.

Published in the journal Cell, the work involved detailed analysis of the genomes of gut bacteria for 70 mothers and their infants. It showed evidence of large-scale mobility of genetic elements from the mothers’ microbiome to their infants.

Microbes Affect Immunity

Though most of us don’t spend much time thinking about our body’s non-human cohabitants, we actually have many species of bacteria, as well as fungi, protists, and viruses that live on us and inside us. Taken together, these microorganisms are called the “microbiome.”

Our bodies’ microscopic cohabitants are not freeloading off of us. Instead, they are helping us with many aspects of our health and well-being, including digestion, circulation, mental health, and our ability to fight disease.

It turns out that the microbial makeup of a baby’s internal microbiome greatly influences their immune system, which is why some experts call the human microbiome the body’s “other immune system.”

The microbiome may be especially crucial during the first year of life, while the infant’s acquired immune system is still coming online. But infants’ microbiomes also affect a variety of other systems’ development, including the infant’s metabolism and even cognitive development.

Infants who are born vaginally pick up important beneficial microbes directly from the mother, as they descend the birth canal and are exposed to the mother’s vaginal flora (as well as their anal flora). The direct transfer of the microbiome from mother to baby is something that researchers have understood for many years. Since infants who are born via cesarean do not get the benefit of being well seeded with the mother’s microbes, a disrupted microbiome is one of the main reasons to avoid having a cesarean birth if possible.

Horizontal Gene Transfer In this new research, however, the scientists found that the infants’ microbes had picked up genes from the mothers’ microbiomes belonging to microbes that had not themselves been passed along. Somehow these bacterial genes were exchanged without the organisms they were part of.

This sort of exchange is called “horizontal gene transfer,” in which genes are passed outside of the organism whose DNA they are a part of. Bacteria engage in horizontal gene transfer all the time and this phenomenon is well documented in the scientific literature in the field of biology.

But the idea that bacterial genes could jump from mother to child was virtually unknown in medical science until now.

With A Little Help From My … Viruses

The researchers found evidence that the gene transfer involved bacteriophages. Bacteriophages are viruses that prey on bacteria, inserting their genome into the genome of the bacteria.

When these viruses commandeer the bacterial DNA, they can free some of the bacterial genes from the bacteria and facilitate the transfer of the genes to other cells, in this case from the mother’s microbiome to the infant’s.

When genes are transferred from the mother’s gut to the infant’s, it influences the metabolism of the infant microbiome. This in turn affects the infant’s own metabolism.

The infants’ microbiomes and metabolisms were very different if they had been exclusively breastfed. Breastfeeding changed the microbiome of the infant in beneficial ways. The researchers found that breastfed infants had hundreds of different metabolic markers that had been metabolized by their microbiomes from breast milk, likely impacting their immune systems, metabolisms, and cognitive development.

Back to our real-world conundrum where N (the number of participants in any given experiment) only equals two. The mom of the girl who is sick all the time told us she believed her daughter’s struggles are because she herself was so sickly as a child and that she disrupted her own microbiome by taking antibiotics for years as a teenager to try to combat acne. What’s more, the antibiotics did nothing to improve her skin, she said, and she regrets having taken them.

The take-away from this new science may be that we all need to pay more attention to the care and feeding of our non-human body-mates. While we can’t go back and change our childhood health practices, we can start implementing microbiome-friendly health habits in our lives from this moment forward.

Eating real food is “pre-biotic,” as it encourages the proliferation of healthy bacteria and other microbes in the body. Avoiding antibiotics, pesticides, and herbicides (in particular glyphosate), which cause damage to beneficial bacteria, is also important.

You can eat probiotic foods as well. These are foods that contain live bacteria that are thought to be health-giving. Probiotic foods include fermented sauerkraut, kimchee, and other vegetables, whole unsweetened yogurt, and kefir.

Vaginal seeding—transferring vaginal flora from the mom to the mouth, nose, and skin of the newborn—for babies who are born via C-section and exclusive breastfeeding will also help cultivate a healthy microbiome for the baby.

About the Author: Jennifer Margulis, Ph.D., is an award-winning science journalist and book author. Her work has been published in the New York Times, the Washington Post, and on the cover of Smithsonian Magazine. A contributing writer at The Epoch Times, she also has a popular Substack called Vibrant Life. A version of this article first appeared in The Epoch Times.


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