OK, brace yourself for some science fiction level stuff in this article. (And if you don’t, then don’t say I didn’t warn you.)  

Like you, I was raised to think of myself as a human being who is living my best life on this planet full of other humans, animals and plants. And, yes, that’s all true. But it’s not quite so black and white. In fact, there’s a 39-trillion strong team of microbes living inside our guts that have a lot to say about our overall health. And recent science has shown us that they play a far more important role than we ever realized. 

Friends, meet your gut microbiome, a community of microorganisms living predominantly in your colon that are made up of (mostly) bacteria, fungi, archaea, parasites and viruses. My favourite? (It’s true, everyone has a favourite kid.) The archaea, which are single cellular organisms that fossil records suggest have been on our planet for 3.8 billion years. You’ll find them miles deep in the ocean hanging in rift vents. They’re also known to call the insides of a volcano home. Oh, and, yeah, they’ve also taken residence inside you — specifically, in your colon. 

Being that most of these microbes are found inside your digestive system, it comes as no surprise that they play a critical role in digestion. They work in teams to unpack your food, allowing you to extract the nutrients you need. For example, they take fibre — yes, boring, often cast aside fibre — and magically transform it into perhaps the most underrated thing in all of nutrition: short chain fatty acids (SCFAs). 

If you’re like, “Why should I care about SCFAs?” then you should know I’m totally obsessed with them. And for good reason: They’re known to strengthen the healthy microbes in your gut and weaken the unhealthy ones. They reverse “leaky gut” by strengthening tight junctions between the gut barrier cells. They also serve as the main energy source for the cells in your colon. Not to mention that they lower cholesterol, prevent type 2 diabetes, optimise the immune system — and the list goes on. Suffice it to say, they’re good! 

But SCFAs are just one example of how gut microbes help us to process our food. Bacteroides bacteria are known to synthesise conjugated linoleic acid (CLA), which prevents diabetes, atherosclerosis (fatty deposits that clog your arteries), obesity, hyperlipidemia (when your blood has too many lipids, or fats), and immune confusion. Another gut microbe all star is  lactobacillus plantarum, which is known to process the anthocyanidins (plant pigments) found in berries to produce compounds that prevents diabetes, atherosclerosis and Alzheimer’s disease. 

Here’s the other thing about your microbiota: They’re tasked with helping you to process not just food, but anything you put into your mouth, including drugs. Which is why the same drugs that can have a life saving effect in one person might have a life-threatening effect in another. For example, the chemotherapy drug cyclophosphamide actually depends on gut microbes to activate it. The healthier the gut, the better the chance at fighting off cancer with this drug, according to a 2013 study published in Science 

Kind of crazy, right? But in case you thought that was it, microbes do so much more than just digest what we consume. For starters, 90 percent of serotonin — the happy hormone that regulates our mood and energy levels — is produced in the gut. Our gut microbes play a critical role in that process. 

 There’s also the fact that 70 percent of our immune system lives in the gut, separated from our microbes by a single layer of cells. The two are in constant communication with each other. If you hurt one then you hurt the other. 

 Microbes also play a critical role in our genetic expression. We’ve seen autoimmune conditions increase 500 percent in the last 50 years and wondered why. Have our genetics changed that much in the last 50 years? Nope. Whahas changed is our genetic expression. And recent studies have shown us that it’s damage to the gut microbiome that actually flips the switch on this gene and activates it. The good news? Ninety seven percent of people who carry the gene for celiac disease never express it. But we have to keep our guts healthy to keep it that way. 

 As if that’s not enough, most of your genetic code is found in your microbiome. If you were to think of the entirety of your genetic code as a 100 meter sprint, your first step would be your human DNA and every step after that would be for your microbial DNA. Kind of crazy, right? 

 So as I step back and consider my place on this planet, I realise that we are not just humans living our best life. We are a part of nature’s balance, and inside of us is this community that we need just as much as they need us — we’re better together! And when we take care of them, they take care of us.