What Is Gut Health And Why Is It Important?
Gut health has become a hot topic in the wellness world for good reason. Many articles are coming up preaching the importance of maintaining a healthy gut, and how an unhealthy one can impact a person’s overall health. If you’re curious about whether or not a healthy gut is is really matters, or why it does, I want to help you answer some of the questions surrounding this topic and provide some helpful information and tips that you can apply to your own life.
So first, it’s important to cover the basis of digestion. Why does it matter, and how does it work? We tend to think of our GI tract as being the inside of our body, but it’s really part of the outside, in the same way that our skin is. Think of your GI tract as a tube that starts at the mouth and ends at the anus. Whatever is inside this tube is still technically outside of the body. Things don’t enter the body until they are absorbed into the bloodstream or lymphatic system from this “tube”. Everything that travels through the GI tract that is not absorbed by the body is technically still outside of the body and is discarded in our stool. So similar to how our skin protects us, our GI tract is intended to protect us as well.
Digestion: How It’s Supposed To Work
Digestion begins with the thought and expectancy of food. Saliva along with mastication starts the breakdown of food before the food moves into the esophagus and into the stomach. The acidity of the stomach sterilizes the food (kills off harmful bacteria and parasites) and begins to breakdown proteins into amino acids. Food then moves into the small intestine, during which the release of bile by the gallbladder helps to emulsify fats into fatty acids and glycerol molecules. Carbohydrates and proteins are further broken down into glucose and amino acids in the small intestine. The villi and microvilli located in the small intestine, as part of the gut barrier, act like filters that allow these nutrients–which include amino acids, carbohydrates, fatty acids, vitamins, and minerals–to be absorbed into the bloodstream and lymphatic system and spread throughout the body for use. The intestinal barrier is also responsible for keeping potential toxins and harmful substances out of the blood stream. Anything that is left unabsorbed, including indigestible fibers, water, and bile is moved into the large intestine where bacteria further feed on the remains and convert them into nutrients like vitamin K2, B1, B2, B12, and butyric acid before waste is excreted in the form of a stool.
So as you can see from my brief explanation, healthy digestion is responsible for some crucial aspects of our health, including keeping toxins and pathogens outside of our bodies and absorbing and producing nutrients to be used for bodily functions, which cannot be done effectively without a healthy gut.
The Consequences of An Unhealthy Gut
An unhealthy GI tract can lead to many health problems that tend to stem from malabsorption–which causes nutrient deficiencies–, bacterial imbalances, and viral/bacterial/parasitic infections. This is largely due to the fact that approximately 70%-80% of our immune systems are located in our guts.
Malabsorption: Nutrient Deficiencies And What They Lead To
Having compromised digestion due to an unhealthy gut can lead to a malabsorption of nutrients that can create nutrient deficiencies. Nutrients are essential for our cells to do anything and everything including metabolizing food, detoxification, healing, and just about anything that you can think of regarding how the body operates. Some of the most common nutrient deficiencies in the U.S. population are iron, iodine, magnesium, zinc, calcium, vitamin D, vitamin B12, and vitamin A. While some of these nutrients are pretty scarce on the standard American diet, some of them are pretty concentrated. For example, zinc and calcium are found in decent amounts in meat, dairy, eggs, legumes, and grains, which are all fairly common foods consumed by the average American. B12 is also often found in animal foods. Unfortunately, compromised gut health can keep us from absorbing the nutrients found in the foods we eat. Nutrient deficiencies can lead to many different illnesses, the most common of which include anemia, thyroid disorders, bone loss, rickets, osteoporosis, cancers, impaired brain function, and cardiovascular disease. The causes of poor digestion can include things like low stomach acid, insufficient digestive enzymes, poor liver/gallbladder function, and bacterial imbalances.
Bacterial imbalances can cause more than just digestive issues. Small intestinal bacterial overgrowth (SIBO) can be defined as an excess of total bacteria or an excess of a particular strain of bacteria in the small intestine. While the small intestine normally does contain small amounts of bacteria, an excess or imbalance can cause damage to the intestinal wall and the villi and microvilli previously mentioned, which can lead to intestinal hyper-permeability (i. e. leaky gut), which can then result in food intolerances/allergies, autoimmune illnesses, digestive disorders, skin conditions, bone/joint conditions, metabolic issues, and even mental health illnesses. SIBO can also exacerbate nutrient deficiencies by feeding on amino acids and B vitamins and disrupting fat-absorption–and therefore inhibiting the absorption of fat-soluble vitamins A, D, E, and K.
The Microbiome & Mental Health
Mental illnesses have become quite common in the United States, with anxiety disorders affecting 18.1% of the U.S. adult population. We know that a compromised gut can cause all sorts of digestive symptoms, but researchers have recently been finding that the gut and the brain are also closely related. A person’s gut is home to trillions of microorganisms of different classes and strains, some of which contain more than 3 million genes. Imbalances in this complex gut microbiome have been linked with many different mental health illnesses and conditions, including anxiety, depression, ADHD, bipolar disorder, schizophrenia, dementia, autism, and obsessive compulsive disorder. One of the reasons for this is neurotransmitter production. In fact, studies that compare the gut microbiomes of individuals with major depressive disorder with those of individuals without a mental health diagnosis, indicate a significant contrast of bacterial strains between the two groups. A large percentage of serotonin, dopamine, and GABA–some of the main contributors to feelings of joy, pleasure, relaxation, and well-being–are actually created in the gut by the microbiome. In cases of bacterial imbalances, neurotransmitter deficiencies can develop and contribute to symptoms of mood disorders.
The Microbiome & Food Cravings
Certain microbes present in the gut microbiome feed and thrive off of different foods. Some prefer fats, while others prefer carbohydrates and fiber. The interesting thing about this is that these microorganisms can influence us, the hosts, to consume the foods that they desire by triggering cravings for them. So in cases of overgrowths, the highly concentrated species may overpower other microorganisms and result in an urgency for the host to consume a particular type of food (sugar cravings anyone?) , which can then lead to a host of metabolic issues like obesity, insulin resistance, and type 2 diabetes. Maintaining a healthy gut microbiome diversity encourages a balance of food cravings rather than a strong and overpowering craving for one particular type of food.
The Microbiome & The Immune System
The array of microorganisms in our guts also affect the strength and vitality of our immune systems, which allows us to fight off illnesses. Our microbiota are actually responsible for developing and regulating healthy immune responses in different manners. The microbiome affects the secretion of cytokines, which influence the activation of immune cells that help fight parasites and secrete antibodies to foreign invaders (including harmful viruses and bacteria). They also help maintain a healthy balance between the pro-inflammatory immune cells (which fight off pathogens) and the immune suppressing anti-inflammatory cells (which shut down immune responses after neutralization). The microbiome also help in the development of the adaptive immune system, which is what allows us to respond quickly and effectively to a familiar infection (like in the case of vaccines). So our gut bacteria directly affect the complexities that make up a healthy and robust immune system.
As mentioned before, poor digestion can lead to what is commonly known as “leaky gut”, which is important for numerous reasons. Leaky gut, or intestinal hyper-permeability, occurs when the intestinal barrier that lines the GI tract becomes damaged and allows things besides nutrients to enter the bloodstream and circulate the body. Pathogens like viruses, bacteria, large undigested proteins, and other toxic waste can then be absorbed into the body and left to be “taken care of” by our immune cells. The adaptive immune system then treats these substances as foreign invaders and launches an attack on them, creating inflammation. As you continue to consume the same foods, the inflammation also continues, and the chances of developing food allergies/intolerances, autoimmune diseases, and other illnesses increase. This is why some people that have been eating, say bananas, every day for years, can one day find themselves having negative reactions to them. Imagine that. You enjoy a food so much that you consume it every day and then suddenly you can longer tolerate it.
What Causes Poor Gut Health?
So now that we’ve covered some of the things that make gut health so important, let’s discuss some of the things that can negatively impact it. The most general cause of poor gut health is stress. Anything that creates a stress response can contribute to a damaged gut. Cortisol is a hormone that is secreted in response to stress and is involved in blood sugar regulation and depresses the immune cells located in the gut (remember, 70%-80% of the immune system is found in the gut). It also increases the permeability of the gut and increases the likelihood absorbing pathogens. High cortisol can also decrease the production of digestive fluids, slow digestion, and possibly alter the gut microbiome. An imbalance of cortisol levels can lead to an unresponsive immune system or an overactive immune system with chronic inflammation. But counteracting this effect is not simply a matter of taking time to binge-watch your favorite show so you can “relax”. All sorts of things can disrupt cortisol levels, including both physical and mental stressors.
Meal Environment & Digestion
Let’s start with the basics. Have you ever felt nervous or anxious about something and then found yourself rushing to the bathroom as a result? This happens because our digestion is directly affected by how we feel through the gut-brain axis, which is especially important during meal times. A person’s mood and environment while eating can have a huge impact on how well the food is digested. A parasympathetic state is essential for the secretion of saliva, stomach acid, and gastric juices and this begins with a person’s mentality. Being in a state of worry, anger, frustration, etc. encourages a sympathetic state, which shuts down the production of digestive fluids. When digestion is compromised in this manner, it opens the door for things like malabsorption, bacterial imbalances, pathogenic infections, and leaky gut. This is why eating in a relaxed state, with good company (or no company if you’re that kind of person), and chewing adequately can do wonders for maintaining the health of your GI tract. And the great thing about this is that it’s absolutely free to do.
The amount of food that a person is consuming can also influence gut integrity. Eating insufficient amounts of food can lead to a deficiency of nutrients that are necessary for every aspect of cellular function. Our bodies use carbohydrates for energy for carrying out all sorts of bodily functions, as well as feeding our gut microbiota adequately. A deficiency in amino acids can lead to an inability to build and repair tissues effectively, including that of the gut. Fatty acids aid in the absorption of other nutrients as well as provide our bodies with energy. On the same note, overeating can cause gut damage by overstressing the digestive tract and not allowing food to be properly digested before being transported throughout the gut. Overeating can also cause excess fat storage, which can also create inflammation and a chronic stress response throughout the body and overcrowd digestive organs.
Chronic consumption of food intolerances specific to the individual can further exacerbate gut inflammation by overriding the immune system. Gluten, which is found most commonly in wheat, is now being suspected as being a contributor to intestinal hyper-permeability in all people, not just those with a gluten allergy/sensitivity. Glyphosate, which is found in Monsanto’s Roundup herbicide, is now being thought to disrupt digestion by inhibiting enzyme production and damaging the microbiome. This herbicide is commonly used in crops like corn, soy, canola, and wheat–four ingredients that are so often used in processed foods. High amounts of sugar consumption can also damage the gut by disrupting cortisol levels and creating an imbalance in the microbiome.
Some of the most commonly used food additives are zero-calorie sweeteners. They seem like a good idea because they provide the sweet taste without the sugar, so it works out right? Well both animal and human studies have indicated that consumption of these sweeteners can negatively alter the gut microbiota and result in metabolic issues like insulin resistance. This is why some people experience immediate digestive reactions–like gas, bloating, and diarrhea–shortly after consuming some artificial sweeteners.
Yes, exercise is an important part of maintaining your health, especially in our modern world, surrounded by electronics, cars, and convenience. A chronic lack of movement creates a stress response, but so does overexercising. Exercise is meant to create a healthy stress response and result in a healthy adaptation to that stressor. Problems arise when a person who is already chronically stressed with work, kids, family, etc. decides to take up a rigorous exercise routine on top of an already stressful life. In such cases, exercise can do more harm than good, increase chronic cortisol and inflammation without allowing the body to heal, and increase gut permeability. Another thing to keep in mind is post-exercise intestinal permeability. Studies have actually shown that our guts are more permeable (i.e. more “leaky”) after a workout, and that consuming food soon after a workout can actually lead to digestive upsets. This happens because rigorous exercise can lead to inadequate blood flow to the gut and make it more permeable as a result.
It may come as no surprise that alcohol also damages gut integrity. Even one night of excessive alcohol consumption can damage the mucosal lining of the small intestine, which increases intestinal permeability. Chronic alcohol consumption contributes to inflammation, can disrupt the microbiome balance, and damage the liver–an organ that plays a major role in energy metabolism, blood sugar regulation, and the digestion of fatty acids (among many other things).
So there are a whole host of things that can go wrong within the gut and so many contributing factors. Gut health also impacts not only digestion but every other aspect of our health from immunity and disease prevention to mental health. The things that we do in our daily lives can very directly impact the state of our guts and our overall health as a result. So if you struggle with certain issues and have never thought to address your GI health, it’s possible that that is at the root of your problem.
I hope you found this information useful, and I’m looking forward to sharing with you some of the more practical parts of a healthy gut in my next post! If you have any questions or comments, feel free to share them below!