This Father’s Day, Thank Dad for Sharing His Microbiome

We all get certain traits from our parents. We might have our mother’s eyes and our father’s mouth; our mother’s adventurous spirit and our father’s facility for languages. Like our mothers, fathers can pass much more than chromosomes to their children; they could also pass their microbiome.

When it comes to the microbiome, mothers get a lot of attention. And for good reason! Besides being all-around amazing, our mothers give us an extra gift: their bacteria. Through a vaginal birth, breastfeeding, or mom’s first hug, we become colonized with her bacteria. This early exposure to mom’s unique bacteria stays with us for life, helping to determine the makeup of our own microbiome which can offer protection against ailments ranging from allergies to diabetes.

While the existing research overwhelmingly focuses on the maternal microbiome, research has shown that our genes can affect the kind of microbiome we develop—and those, of course, are half Dad’s. Beyond this, numerous studies have shown that living together encourages bacterial exchange, giving fathers plenty of opportunity to shape the microbiomes of the children that live with them.  

In honor of Father’s Day, let’s celebrate the ways your Dad and his microbiome are always there for you.


It’s all in the genes

Like most things that make us unique, our microbiomes are determined by a combination of genetics and environment. Several studies have found that our genes may influence our microbiomes, meaning that Dad may be influencing your microbiome more than you know.

Indeed, scientists have been able to determine that certain bacterial strains are more heritable (or able to be inherited) than others, with heritable strains like Christensenella minuta affecting metabolism and others influencing immunity and digestion. It’s possible that our genetic composition makes our bodies more or less hospitable climates to various bacterial strains, and that in turn shapes our own traits like immunity and lactose tolerance.

Since you inherited half of your genes from your father, you’re likely to share some of his microbiota, even if you never lived together. Turns out that neither the apple – nor the microbiome – fall far from the tree.


Sharing a home and a microbiome

The first time a father cradles his newborn child in his arms, something amazing happens. Yes, the spark of profound parental love, but we also mean the beauty of bacterial transfer. While mom’s vaginal microbiome provides the first exposure for children born vaginally, skin-to-skin contact immediately after birth helps colonize the newborn with a robust collection of microbiota. Doctors recommend this skin-to-skin contact for positive health benefits all around.

The bacterial effects of being close to dad don’t end at the hospital, however. Numerous studies have shown that families share similar microbiomes with similar bacterial strains. Meanwhile, one 2014 study found that children’s gut microbiomes were equally similar to their mother’s and father’s, indicating that the effects of the parental microbiome go far beyond birth. The effects of cohabitation were so strong that in the same study, even cohabitating partners shared remarkably similar microbiomes, despite being genetically unrelated and having lived apart from each other the majority of their lives.

Even though we get our microbiomes from both of our parents, Dad’s microbiome seems to play a unique role in introducing family members to diverse bacteria species. One 2018 study found that fathers are more likely to introduce novel bacteria strains to the rest of the family, boosting the other family members’ microbial diversity.


If mom says no, ask dad

It’s a common stereotype that fathers are more lax than mothers, especially when it comes to issues of cleanliness. While that’s not true across the board, if your dad did let you roll around in the dirt as a child, was a diehard champion of the “five second rule”, and said yes to that adorable puppy, he may have given lifelong gifts to your microbiome.

In a number of studies around the world, researchers are proving that the bacteria Mycobacterium vaccae found in soil could be vital to our health. Additionally, saying yes to the dog ensured that you were exposed to the immune-boosting effects of Fido’s microbiome. And let’s face it: rolling around in the dirt can be fun–especially with a dog!
So all hail Dad! Let’s give him a round of applause for all the ways he is an unsung microbiome hero: from the DNA he gave you at conception, to the first time he hugged you as an infant, to all those little habits you thought were just dad being dad. This Father’s Day, say thanks to your old man for his love, wisdom, and bacteria.