C-Section Babies Have a Different Microbiome

A couple of very extensive studies have found that babies born by c-section have a very different microbiome (microbes and bacteria) than babies born vaginally. And, while it’s too early to make anything more than correlative guesses, the early lack of those vaginally born “bugs” might account for the higher prevalence of allergies, intolerances, and illnesses prevalent in babies born by c-section.

What Is the Microbiome?

The term microbiome is in vogue lately, but what it actually is remains unclear to many. Simply put, a microbiome is the genetic material of all the microbes (aka viruses, bacteria, fungi, and “bugs”) living in a place. Each one of us has microbes living on our skin and inside our bodies, namely our lungs and gut. Many of these are necessary and vital; some are innocuous.

But we don’t have this microbiome in utero; Science Daily says that humans are born “germ-free.” It’s during the birth process these bacteria begin to stick, taking up residence everywhere from our skin to our gut.

There’s a link between the types of bacteria and bugs we might have, and our general health overall, although science has just started to explore this hidden world linking our microbiome to better living overall.

The Sanger Institute puts it this way, “Our gut microbiota can be thought of as an ecosystem – thousands of species and millions of individuals living together, interacting with each other and with their environment. Uncovering which are important for disease, and how they might be harnessed to improve health, is no easy task. Understanding where it comes from is an important piece of the picture.”

Plus, a person’s microbiome can change in different places in the body; antibiotics, for instance, can temporarily change the gut microbiome. Usually, even though there might be temporary upheaval, a person’s microbiome returns to a state of equilibrium eventually.

Not All Births Create the Same Microbiome

There have been a couple of recent studies regarding the differences in the microbiomes of c-section babies versus babies born vaginally. For instance, a vaginal birth seems to gift the baby with bacteria from the mother’s gut, which might stimulate immune responses.

Without that short trip down the birth canal, though, the microbiome is plucked from the hospital rather than the mother.

“This may explain why, epidemiologically speaking, cesarean-born children suffer more frequently from chronic, immune system-linked diseases compared to babies born vaginally,” Associate Professor Paul Wilmes of the Luxembourg Centre for System Biomedicine said to Science Daily.

Indeed, microbiomes are shockingly different. A UK study by the Wellcome Sanger Institute, published in Nature, analyzed over 600 newly born babies’ microbiomes. The c-section babies had many disease-causing pathogens.

Trevor Lawley, a microbiologist for Wellcome Sanger, said the c-section babies had high levels of Enterococcus and Klebsiella, found commonly in hospitals. “I could take a sample from a child and tell you with a high-level certainty how they were born.”

If You Have a C-Section Baby, Relax

Although the UK study, called the Baby Biome Study, found the microbiomes of c-section babies were completely disparate from the vaginal birth babies, it also found the microbiome seemed to correct itself over time.

Nature stated that “Months after birth, however, the infants’ microbiotas grew more similar — with the exception of a common genus of commensal bacteria called Bacteroides.”

Bacteroids were absent in the c-section babies at birth, and about 60% of the babies still had little to none of the strain nine months later. Bacteroids, via previous research, are thought to influence the immune system and discourage inflammation.

Still, there’s no reason to panic. And forget about the idea of “seeding” that c-section baby with vaginal fluids to somehow balance out the microbiome. Not only has that been proven ineffective, it’s also thought to possibly pass on harmful microbes to the newborn.

Research is ongoing and large scale; the Baby Biome Study’s next step involves a possible 40,000 participants (if Wellcome Sanger’s funding goes well). That should be a large enough sample size to garner more definitive results.