And nutrition plays a major role in the health of your gut microbiome. One study found that dietary factors like the amount of fats, fiber, starch, sugar, probiotics and protein we consume can impact the health of our microbiome.

You may be thinking, "And?"

And the health of our microbiome can impact both physical health, like disease risk and outcome in the case of diabetes, obesity and psoriasis.

And mental health, like mood disorders. One study even found a link between gut microbes and the production of serotonin, the chemical that promotes mood stabilization and healthy sleep. Bouzamondo concurs.

"Nutrition is perhaps the most significant modifiable factor in promoting the formation of a healthy microbiome, and a healthier you," he said.

In fact, some foods, such as those containing dietary fiber, can serve as fuel for microbiota (the microorganisms of a particular site or habitat, like your gut), promoting gut health, while others containing protein can promote potentially harmful byproducts that sit in the gut. Not a reason to neglect the daily protein we need, just some food for thought.

It's also been found that healthy dietary patterns consisting of high-fiber vegetables like spinach and broccoli, nuts, fish, eggs, seeds and whole grains are tied to a diverse gut microbiome, and ultimately, lower risk of chronic diseases.

So, if you really are what you eat — from your risk of disease to your brain health to your general mood — as Bouzamondo said, "take it easy on your gut. It's working harder for you than you may realize."