What is the Gut Microbiome? A Quick Overview
Inside your intestinal tract live about 100 trillion bacteria that form a symbiotic community that’s responsible for the regulation of many of our bodily functions. (1, 2)
Experts now believe it should be considered an organ, just like your heart or lungs. (3)
And that’s exactly how critical this community of microorganisms is to your health. (4, 5)
Without it, our immune systems couldn’t function properly, and neither could our brains. (6, 7) It’s an extremely complex and completely crucial part of how our bodies function.
So, why is everyone starting to discuss this ‘microbiome’ now — the mysterious organ that we didn’t learn about in school? Because the gut microbiome plays a key role in our overall health, and we have the power to influence it.
Unlike most of our organs, the microbiome isn’t a static, unchanging entity. It’s constantly being altered and re-populated by what we eat. (1, 8)
In the same way we can use exercise to improve our physical fitness and heart health, or lift weights to build our muscles, we can take specific actions to optimize our gut microbiome. (9, 10)
When you consider the sheer number of microorganisms living in your gut (in the average person there are over 4 pounds of microscopic organisms and more than 1000 different species in there!), it brings a whole new meaning to the adage, “You are what you eat.” (2)
What Does the Gut Microbiome Do for Our Health?
Breakthroughs in science and technology are uncovering the many ways that the gut microbiome influences overall health. Based on these advancements we now know a lot more about how your gut is the control center for your health (and we are learning more about this amazingly complex ecosystem inside of us every day).
Some of the critical bodily functions these bacteria are responsible for include:
- Immune system regulation (11, 12)
- Food digestion (13)
- Blood sugar regulation (14, 15)
- Vitamin production (2)
- Brain chemical influence (7, 16)
- Heart health management (17)
Basically, there’s not much that goes on in your body that doesn’t involve the gut microbiome in some way.
If you are dealing with a nagging health issue, odds are it may be connected to your gut.
The Gut Microbiome Impact
Because of all the ways the gut microbiome impacts bodily functions, it’s understandable that a balanced and healthy microbiome = a healthier person. (5)
And unsurprisingly, research concludes that many diseases that plague modern society correlate to the health of the gut microbiome.
Diabetes
Diabetes and pre-diabetes have been directly tied to gut microbiome health. Significant compositional differences in gut microbiota have been observed between diabetic groups and non-diabetic. (18, 19)
Although the research regarding the relationship between microbiome and metabolic syndromes is still emerging, more and more evidence suggests that microbiome dysbiosis plays an essential role. (20)
Amazing, right? It is really hard to imagine that the tiny bugs inside the gut are so important to metabolism homeostasis. While it might be too early to talk about intervention of diabetes via the gut microbiome, based on current clinical evidence, increasing butyrate (one of the short-chain fatty acids we discussed earlier) producing bacteria and supplementing Lactobacillus and Escherichia species with metformin could be a potential approach to managing blood sugar more effectively.
This gives massive amounts of hope to those battling diabetes or pre-diabetes because it means effective blood sugar regulation may be influenced by a balanced gut microbiome.
Heart Disease
Your heart health is also influenced by the strength of your microbiome. Emerging science is observing relationships between the health of the gut and cardiovascular health. (17, 21)
Keeping the gut strong can increase healthy cholesterol levels and decrease chemicals known to cause artery blockage.
In some studies, probiotic supplementation has also been shown to positively impact lipid profiles. Probiotics are live cultures of bacteria that, when properly selected and delivered in adequate amounts, can increase the presence of healthy bacterial colonies in our guts.
For these reasons, we have to focus on making our gut health a top priority for better heart health.
Intestinal Diseases
It’s probably no surprise that the gut microbiome significantly affects overall digestive health since it is located at the center of your digestive system. In fact, the gut microbiome plays a crucial role in maintaining proper digestive health by helping improve bowel regularity and decreasing symptoms of gas, bloating, diarrhea, and leaky gut. (13, 25, 26)
However, beyond those basic digestive functions, research is also uncovering a direct parallel between certain gut bacteria species and chronic diseases like irritable bowel syndrome (IBS), inflammatory bowel disease (IBD), Crohn’s disease, ulcerative colitis, celiac disease, and even colorectal cancer. (27, 28, 29, 30, 31)
You see, when the bacteria in the gut process certain types of undesirable food, they produce gases and byproducts that can be toxic to the intestinal tract at worst, and uncomfortable at best. (25)
Luckily, as with heart disease, reviews of the available data indicate that if probiotic and prebiotic supplementation is done correctly, it can support healthy management of intestinal disorders. This involves identifying the correct beneficial species and nutrient sources that will create positive bacterial changes in the gut.
Again, it’s great news for all of us who are striving for good digestive health, as it appears the stronger the good bacteria in our microbiome, the better our digestive system functions.
Obesity
In many ways, the health of your microbiome can have a direct impact on your weight. That’s right, studies show that a having high-functioning and diverse colony of bacteria in your gut means you’re less likely to be obese.
A healthy gut means your metabolism can function at its best. After all, your gut is the place where food gets digested, so it can affect the absorption of nutrients and storage of fat. And, when certain species of health-promoting bacteria decline within the microbiome, metabolic health declines as well. (14)
Furthermore, this phenomenon has even been observed in twins. This means that even when two people have practically the same genetic makeup, they can have completely different microbiomes — giving researchers hope that targeting and modulating the microbiome (either therapeutically or through strategic nutritional intervention) can reduce the incidence of obesity.
The gut microbiome also synthesizes certain vitamins, which can impact weight gain/loss. Vitamin K and certain B vitamins are produced by the microbiome colony. (59)
Mental Health
In what has been dubbed the “gut-brain connection,” scientists have discovered in more detail the mind-blowing ways in which the microbiome directly influences our levels of anxiety, depression, and overall mood. (7, 35, 36)
In fact, up to 95% of serotonin (the happy hormone) can actually be found in the gut, not the brain. So in many ways, our happiness is directly connected to the levels of a healthy digestive system and the associated bacteria we have in our gut.
While science is still trying to figure out exactly how to treat these mental health conditions, specifically through altering the microbiome, one thing is clear: people with depression are missing certain species of bacteria from their gut.
What Lives in the Gut Microbiome: Good Guys and Bad Guys
Most of the bacteria that comprise the microbiome are there for your protection and benefit. These “good guys” form a type of army that provides defense and protection for your entire body. (39)
Imagine having an army of a trillion microscopic organisms overwhelming and destroying almost anything that tries to compromise your health…this is exactly the way a properly functioning and balanced gut microbiome works.
But when things in the gut become unbalanced, the other, more sinister “bad guys” can start causing problems.
There are plenty of strains of what we may consider pathogenic bacteria, viruses, or fungi that have their place in very small numbers in a normal gut microbiome. The problem is, when the good guys aren’t flourishing, a void can be created that the bad guys quickly fill…and they’re able to wreak havoc on your health.
When the good guys aren’t strong enough to keep opportunistic bad guys in check, they produce toxins that wear down the lining of the colon, allowing these bad guys to escape and infect the bloodstream or tissue. (39, 41) This is where you get sick. Really sick. They can also cause inflammation in your body and can even lead to chronic diseases.
And this is why we want to make sure we do whatever we can to promote the health of the good bacteria — they will simply take care of the bad ones for us, allowing us to stay in control of our health and minimize the chances of getting chronic diseases.
Improving the Gut Microbiome for Specific Healthful Results
So, how exactly do we most effectively encourage the good guys and eradicate the bad guys within the gut?
There are a few key ways to accomplish this task.
1. Prebiotics
Prebiotics are the most potent tool in the fight against bad gut bugs in the colon.
Prebiotics are fibrous and fermentable superfoods that feed the beneficial bacteria in your gut and make them strong. (42)
There are a few different types of prebiotics, most of which are categorized by the FDA as dietary fibers as they mostly pass through your digestive system without breaking down or being digested and have beneficial properties on your health.
One particularly powerful class of prebiotic fiber is called resistant starch, which is a unique type of carbohydrate that bypasses digestion in the small intestine and is slowly fermented in the large intestine. When resistant starch is consumed, a very important byproduct is produced called short-chain fatty acids (SCFAs) — butyrate being one important example. (46) SCFAs have been identified as the primary mechanism through which the microbiome promotes healing throughout the body, including providing additional benefits on overall colonic health, leaky gut, and much more.
Furthermore, these resistant starches help control blood sugar levels, help you manage blood lipids, and offer the benefits of fiber without increasing your “net carb” consumption. (51, 52, 53)
Basically, they’re the key to maintaining a proper balance in your gut microbiome and, ultimately, your entire body.
2. Probiotics
Also known as beneficial bacteria, incorporating probiotics into your gut health regime can be another effective way to improve the diversity and health of your gut microbiome. There are multiple strains of probiotic bacteria that have been researched to promote the health of your gut. Unfortunately, the reality is that not all probiotics are as reliable as we’ve been told to think they are.
In fact, probiotics found in some supplements and food products fail to even reach the gut in large enough numbers to colonize and produce beneficial effects in the body. This is true for a few reasons. First, some probiotic strains have difficulty surviving the harsh, acidic digestive tract. So, these kinds of probiotic strains don’t actually make it all the way to your gut in order to make a difference in your gut health.
Secondly, while there are many researched strains of beneficial probiotics, everyone’s microbiome is unique. Only a few commercially available probiotic strains that are well-studied and are the ones that you specifically need, are the same ones that are being used in store-bought probiotics.
And lastly, even if enough of the probiotic bacteria survive the digestive process and make it to the gut, it’s likely those beneficial strains of bacteria might eventually die off. This is because probiotics need to consume abundant amounts of prebiotic fiber to effectively grow (in strength and numbers) and colonize — and almost none of us get enough fiber in our diets!
3. Rest
One of the most important things we can do for our health is to prioritize sleep. And, as it turns out, our gut microbes like it when we rest too. Recent studies are linking the health and diversity of the microbiome to the quality of sleep and vice versa. It’s another important reason to try to squeeze in those crucial 7-9 hours of sleep each night.
4. Reduce Stress
The gut microbiome is negatively affected by stress. Emerging research on the gut-brain axis indicates that the connections between your gut and your brain are strong and bi-directional. In other words, maintaining a healthy gut microbiome can improve mental health, and reducing stress levels can support a healthier microbiome.
To improve your microbiome health, you should evaluate places in your life where you can effectively reduce stress (of course, that is sometimes easier said than done). You may want to consider meditation or other self-care rituals that help you maintain a healthy sense of balance in your life—both have been shown to lower stress levels.
Your Gut Microbiome — The Key to Vibrant Health
The gut microbiome, the organ you didn’t even know you had, is truly one of the most impactful areas of the body to target when looking for ways to improve health.
By supporting the good bacteria in our guts, we’re supporting our entire body.
From weight control to blood sugar regulation and mental health, the healthier our guts are, the healthier we are.
