Like many of you, throughout my childhood and into my twenties, I thought microbes were something bad – something you had to eradicate with antibacterial soap, mouthwash and household cleaners. Wherever germs lurked, we would seek to eliminate them. But in reality, our microbiome, made up of trillions of microbes, is keeping us and our planet healthy. Nowadays, there are hundreds of scientists all around the world investigating how these microbes impact our gut health, oral health, immune system (especially allergies and asthma), cardiovascular system and mental health.
This is a topic I feel deeply passionate about, which is why I’m so excited to share this post with you today! When I was a little girl my mom worked in the Microbiology department at Toronto Western Hospital where she would watch bacteria grow on Petri dishes and identify them so that patients would know what bacteria was causing their sore throat. (I even remember her bringing home some Petri dishes for me to grow my own bacteria for one of my science experiments.) It was pretty cool then but fast-forward 30 years later and what science has uncovered (and what we still have yet to learn) as it relates to the microbiome is simply mind-blowing.
I’m going to stick with the basics in this post, and in the coming weeks and months, I’ll share more of the latest research on the microbiome as it relates to our gut, skin, mouth, lungs and brain.
What is the microbiome?
It’s the community of microbes, including bacteria, viruses, protozoa, algae, yeast and fungi that live on and in us with the majority living in our gut. These microbes are our constant companions through life because they’re always with us – in sickness and in health.
We have microbes in every nook and cranny of our body, especially our armpits (blame microbes for your stink!).
Here are some cool facts about your microbiome:
Our large intestine is a popular place for microbes to hang out as it is home to 10 trillion microbes and 500 to 1,000 different species.
There are 100 billion microbes in a single gram of poop!
Our gut microbiome collectively weighs as much as our brain, which is why many scientists consider the gut microbiome an organ with its own distinct metabolic and immune activity and have dubbed it the “Second Brain”!
Our hand houses more microbes than there are people on earth.
In one square centimetre of skin, there are one billion microbes!
Our microbes make up about 43% of our body’s total cell count.
We obtain a massive amount of bacteria that help to form our gut during a vaginal birth when we literally swallow and get covered in our mother’s vaginal microflora.
We have far more microbial genes (possibly up to 20 million) whereas we have only 20,000 human genes.
Microbiologist and professor Sarkis Mazamanian says what makes us human is the combination of our own DNA plus the DNA of our microbes.
I would say that we are more microbial than we are human, not that I’m going to argue with a scientist, of course!
So who’s really in charge here? Something we can’t even see with the human eye, something that’s so small millions of them can fit on the tip of a needle – our microbes? Before I get into the benefits of these microbes, I want to dive into where it all began.
How did these bugs get in us and on us?
If you’ve watched One Strange Rock on Netflix (you’ve gotta watch it!!) you already know that the breathable air we enjoy today was formed 2.8 billion years ago by none other than microbes! So that’s where life began.
As for us humans, scientists were in disagreement for many years (and they still are) as to whether a baby is "germ-free" before it travels through the birth canal or has it’s very own fetal microbiome in the womb. That being said, this study found that species typically found in the oral microbiome were also found in the placenta. What we do know for sure is the following:
When a baby is born via vaginal birth and travels through the birth canal, they swallow loads of beneficial vaginal and fecal microbes from mama, such as Bifidobacterium and Lactobacillus. Now that’s a birthday present!
This begs the question, should C-section-birthed babies get wiped with vaginal fluid in a “bacteria baptism” of sorts? Not all scientists are in agreement with this.
More microbes are adopted when that baby is licked by a dog (I always encourage this with my daughter even though we don’t have a dog!) or when a baby is exposed other people like when Grandma and Grandpa visit us as they have their own unique microbiome.
A very scary realization is that bacteria called B. infantis that’s been the dominant bacteria in babies for all of human history is disappearing from babies in the Western World. Could antibiotics and antibacterial products that people use on a daily basis be to blame? Or the rise in C-sections and infant formula? I will save that for another post.
What are the benefits of these microbial communities?
I’m going to keep this section brief because I want to dive deeper into the benefits with a blog post for each area the microbes impact, from gut health to mental health. So although this list is short, the benefits go far beyond what I’ve listed here.
They educate the immune system. A diverse gut flora established in early life with many types of bacteria, fungi and other microorganisms, is crucial for teaching the cells of the immune system what’s good and what’s bad. The mucosal lining of the gut is protected by the microbes that hang out there. This protects the inside of the body (note: the entire GI tract is actually considered the outside of the body) so that foreign invaders or bad bacteria (salmonella, for example) do not get absorbed into the bloodstream from the gut. These microbes reduce intestinal permeability.
Produce 13 essential vitamins. These nutrients are essential for us to thrive and for our immune system to function. They include the water-soluble vitamins thiamine (B1), riboflavin (B2), niacin (B3), pyridoxine (B6), pantothenic acid (B5), biotin (B7 or H), folate (B11–B9 or M) and cobalamin (B12) and C and the fat-soluble vitamins A, D, E and K. These are absorbed in the colon whereas dietary nutrients (these same vitamins we get from food) are absorbed in the small intestine. Thank you microbes!
Aid digestion. Certain microbes break-down the food we eat, such as the polysaccharides found in fruits and veggies, legumes and grains and other plant foods. These are broken down into something called Short Chain Fatty Acids (SCFA), which have an abundant number of benefits from reducing inflammation in the gut, decreasing obesity and insulin resistance and serving as food for other microbes.
Protect the gut from food poisoning. Research has shown that certain microbes prevent intestinal infections caused by salmonella and pathogenic E. coli. This is why two people can eat the same food and ingest the same pathogenic bacteria but only one gets sick – the difference is the microbes that live in the gut.
This is the tip of the iceberg in terms of what the microbiome does for us, and the science is absolutely exploding. Not all that long ago, we thought all microbes were "germs" and this notion that all bugs should be eradicated still persists today but I think it's slowly changing.
Now that we know the importance of the microbiome, it only makes sense for me to follow up with a post on how to keep your microbiome healthy.
In the meantime, if you want to read more about overall gut health and recipes and tips for supporting your microbiome here are some of my favourite posts:
Have a joyous week!