For the next installment of our gut health series, we’re dishing on all things gut microbiome. Ok, maybe not all, because it is a vast and complex topic--but the information that follows will give you a foundation of what you need to know about the trillions of microorganisms that live in and on you. (Cue the brain explosion emoji.)
We wanted to give the microbiome a moment in order to reiterate the opening line of this series: gut health IS health. Our microbiomes are a large part of that. We believe eating well should be motivated by feeling well, and a happy microbiome will help with that.
Interesting. So what is a microbiome, anyway?
The term microbiome can refer to a few different things. It can refer to the microorganisms in a particular environment, like those found on and in your body, or to the combined human, animal, and environmental microorganisms that surround us. For the purposes of this blog, we are going to focus on the microbiome of your gut.
Your gut microbiome is composed of bacteria, fungi, viruses and other fun things that colonize your insides, particularly your large intestine. These bugs are critical to human development, immunity, nutrition, and the central nervous system. The trillions of cells in your microbiome potentially outnumber the cells in your body, and in total your microbiome weighs from 2-5 pounds--the same size as your brain. That’s a lotta microscopic bugs!
These microorganisms are mainly bacteria, and just as a reminder, not all bacteria is bad! In fact, most of it is harmless, and much of it is very beneficial.
The 38 trillion microorganisms in my GI tract sound busy! How are they affecting my overall health?
The gut microbiome lives mainly in the large intestine and helps us digest food, regulate our immune system, and prevent disease. How so, you ask? Your microbiome is like the red velvet rope and imposing bouncer at the entrance of the nightclub that is your insides. It helps maintain the gut barrier (red velvet rope), making it harder for the bad stuff to get inside your body, while supporting your gut in deciding what actually permeates that barrier and makes it in (much like a bouncer). It helps create an acidic environment in your gut that is inhospitable to alkaline-loving bacteria, like a DJ filling the room with bumpin’ music and a vibe that no bad mood could survive in...or has the nightclub analogy gone too far?
Your microbiome is involved with processes, like digesting fiber and producing short chain fatty acids, helping organize and direct your immune system, producing vitamins, and we are starting to know more about the relationship between the microbiome and the central nervous system, which effects brain health.
Noted. So how do I keep my microbiome in tip top shape?
As you can see, there is almost no bodily function that is not somehow related to the microbiome, so the health of it is very important. Particularly, the diversity of your gut microbiota is related to your overall health in ways we are just beginning to understand. The human microbiome is currently being mapped, which means a lot of really smart people are attempting to answer really hard questions around the how and why of our microbiomes. We do know that things like diet, sleep, exercise, and stress can affect the composition of your microbiome over time, and perhaps even on a daily basis.
Some eyebrow raising facts: according to research, the gut microbiome is different between obsese and lean twins. And it gets even more interesting: obese twins have lower diversity of bacteria and higher enzymes, meaning they are actually more efficient at digesting food and harvesting calories. But before we call that a win, obesity has been linked to poor combinations of gut microbiota, which leads to poor outcomes. The more diverse your microbiome-- which naturally happens as you grow, and especially happens when you eat a diverse and well-rounded diet--the healthier it is.
The truth is, there is still much we do not know about the microbiome. There is certainly no singular working model on what a healthy microbiome looks like--they are unique to each of us. We are diverse, and so are our microbiomes!
From the BMJ, here is a handy rundown of what we do and don’t know when it comes to our microbiome and overall health:
What we know
- Probiotic supplementation has several beneficial effects on human health.
- The microbes in our gut influence human energy and metabolism.
- Diet and medication have a strong influence on gut microbiota composition
- Microbiota composition influences response to chemotherapy and immunotherapy
- Microbiome composition defines glucose response to foods and can be used to personalize diet
- Dietary fiber intake influences gut microbiota composition and is related to better health
What we don’t know
- Are natural probiotics in food better than probiotic supplements? Should we take them preventively?
- Can microbes influence food choices and appetite?
- Do low dose antibiotics in food affect human health?
- What is the effect of pesticides in food on the gut microbiome? Is organic food better for the gut microbiota?
And there it is, a first pass on the microbiome. The next time you make a decision, remember you're not only making it for you, but the trillions of microorganisms that reside in and on you. No pressure!