Go With Your Gut to Decrease Chronic Disease and Improve Body Composition
article by Shannon Dahlum
More than 2,000 years ago, Hypocrates, the father of modern medicine, suggested that all disease begins in the gut. While it may not be true of every disease, evidence now shows that most modern chronic disease is indeed rooted in imbalances within the gut. Because of the impact it has on inflammation, immune health, and nutrient absorption, every system of your body is affected by the functioning of your gut.
The digestive tract is arguably the leading cause of inflammation throughout the entire body, which is the underlying cause of a variety of symptoms. Systemic inflammation keeps the body in a chronic state of stress which can lead to chronic fatigue. Inflammation can also have a neurological impact, causing brain fog or symptoms of depression and/or anxiety by altering neurotransmitters, which are your “happy mood” chemicals. It’s also been said that your skin is a reflection of your gut, and indeed, inflammation in the digestive tract can cause inflammatory conditions of the skin, like acne or rashes. Your sex hormones are also altered by inflammation which can cause menstrual and menopausal symptoms in women, fatigue and low libido in both sexes, and erectile dysfunction in men. Your body’s ability to use thyroid hormone can be damaged by inflammation, and even symptoms of insomnia have been documented as a result of inflammation in the digestive tract.
The greatest concentration of immune cells in your entire body exists in your small intestine, so if there is bacterial imbalance or inflammation there, immune symptoms will likely follow. These can include Hashimoto’s hypothyroidism, celiac disease and gluten intolerance, irritable bowel syndrome, food allergies and intolerances, rheumatoid arthritis, and any other autoimmune condition.
Of course, if your digestive tract isn’t healthy, your ability to digest and assimilate nutrients will be compromised. This is known as malabsorption, and it can manifest in many ways. Being unable to properly assimilate protein and fat can lead to dry or thinning hair, and dry or aged skin. Various nutrient deficiencies can lead to fatigue, brain fog, depression, hormonal imbalances, and others. When the brain senses a deficiency in nutrients, you’ll experience cravings for sugar, simple carbohydrates and fatty foods. You may also experience fatigue and slowed metabolism, leading to weight gain, high blood pressure, elevated cholesterol, and high blood sugar.
Clearly, your gut has a massively far-reaching impact on your health. It can affect everything from your mood to your metabolism, your energy to your skin. But what exactly is your gut, and what is it that determines how healthy or unhealthy it is?
The “gut” is a term that refers to your entire digestive system. It begins with your mouth and extends through the esophagus to the stomach, through the small and large intestines and ends with the rectum. This system is lined with a dense mucosal barrier, which serves to keep toxic material from entering the bloodstream. You can actually think of your digestive system as “outside” of your body. It’s designed to break down and assimilate the nutrients your body needs while shuttling harmful materials from your mouth to the toilet without letting them enter other areas of the body. The healthy functioning of the digestive process relies heavily on the integrity of the mucosal barrier, and also on the ecosystem of bacteria and fungus that live within it.
It’s recently been discovered that the human body contains more bacterial cells than human cells. Almost every surface of your body (including your gut, skin, lungs, and urinary tract, for example) has its own bacteria living on it. Your gut alone contains roughly one trillion microorganisms, consisting of one thousand different species. The microbiome is best thought of as a virtual organ of the human body. These organisms do a lot of the heavy lifting in the digestive process (namely in the small intestine, which is responsible for 90% of caloric absorption) by fermenting indigestible fiber. The result of this fermentation process is gas and the production of short chain fatty acids (SCFAs). Some of these SCFAs play a role in appetite regulation and in cholesterol and fat metabolism, while others are responsible for killing off cancer causing cells in the colon, for beneficial effects on blood sugar and metabolism, and for maintaining a healthy oxygen balance in the gut which helps to support a healthy microbiome environment. If you aren’t giving the organisms in your gut enough fiber through your diet, the fermentation process won’t happen and you won’t get the benefits of those SCFAs. You’ll also be starving those organisms of their energy source, so they’ll essentially die out. This is one reason fiber intake is so vital for your health. American adults average a daily fiber intake of 10-15 grams, while 25-30 grams daily is the recommendation given by the American Heart Association.
Other foods that support the diversity of your microbiome are probiotic rich foods. These are foods and beverages that have been fermented, like yogurt, kefir, kombucha, sauerkraut and kimchi. Taking probiotic supplements introduces added bacteria to your gut, as well, but varying the supplement you take is a good idea, to ensure variation in the bacteria you’re receiving. Additionally, if you have an overgrowth of pathogenic bacteria in your gut, supplementing with probiotics can exacerbate imbalances. It’s important to work with a health professional who can help you determine if supplementing is a good idea for you. There are also home stool tests available (one called Viome, for example) that can tell you about the quality of your microbiome and offer specific recommendations for improving it.
Different species of organisms feed on different types of foods. This is why, to support a healthy environment containing a wide variety of organisms, you need to include a wide variety of whole foods in your diet. Limiting your diet to large amounts of simple carbohydrates with minimal fiber, for example, will support certain types of bacteria and fungus while starving out others. This leads to unhealthy imbalances and overgrowths that can cause digestive woes like IBS, but can also contribute to conditions like hypothyroidism and celiac disease. It has also been observed in clinical studies that having a wider variety of organisms is associated with healthier body composition, while a more limited microbiome is associated with obesity and metabolic disease. Going on a very restrictive weight loss diet may provide some short term benefits, but the lack of variety in the diet can eventually lead to disruptions in the microbiome that eventually enhance weight gain. One fascinating study in 2013 took the gut bacteria from a pair of identical twins, one of whom was obese and the other lean, and transplanted it into different healthy mice. The mouse that received a transplant from the obese twin became obese, while the mouse who received a transplant from the lean twin didn’t. This demonstrated that obesity could be induced simply by modifying the microbiome.
Your environment also plays a significant role in the quality and variety of microorganisms that exist in your gut. Bacteria lives abundantly all around you, and exposure to these organisms is vital. Organic soil is teeming with bacteria and this is transferred to the plants that grow in it, as well. Playing in the dirt and eating organic produce provide enormous benefits to your microbiome. Unfortunately, the majority of food you have access to in the grocery store has been treated with pesticides and herbicides which destroy bacteria, both harmful and beneficial. One of the most common herbicides used in farming and probably your own yard, glyphosate (found in Round-Up), is actually an antibiotic. Treating plants and soil with this chemical kills all of the bacteria living on and within them. Not only are you then deprived of receiving these healthy organisms, but when you ingest the chemical, it also damages the organisms you already have in your gut. On the other hand, picking an organic basil leaf off of a plant in your backyard and eating it without washing it is incredibly nourishing to your microbiome. Exposing yourself to healthy microbes is especially important right now, with all of the exposure prevention measures you’ve been taking over the past couple of years because of the viral pandemic.
In addition to a healthy ecosystem, the gut requires a sturdy barrier to prevent outside materials from entering other areas of the body through the bloodstream. This is the role played by the mucosal barrier; a thick mucous lining that covers the entire digestive tract. This semipermeable barrier allows absorption of nutrients while limiting the transport of harmful antigens and microorganisms. When the integrity of this barrier breaks down, microbes from your gut and molecules from items you ingest are able to penetrate through the barrier and enter the blood stream. Remember, the digestive system can be thought of as “outside” of the body, but when the barrier is compromised, things that should remain outside of the body are now allowed in. This is similar to the difference between exposing your healthy, intact skin to harmful bacteria, and exposing a cut on your skin to harmful bacteria. With the skin intact, the bacteria stays on the outside and causes no harm. When the barrier of the skin is compromised by a cut, bacteria is able to enter the body and infection can occur. When unwanted molecules and organisms enter the body through the gut because of a damaged mucosal barrier, the immune system responds to get rid of the foreign invader. When the immune system is chronically reacting to foreign invaders from the gut, it can lead to autoimmune conditions and chronic inflammation.
The mucosal lining in the small intestine is thinner than in other locations throughout the gut, making it more prone to damage. Remember, this is also where 90% of the calories you consume are absorbed. This is why the health of the small intestine is so impactful on immune conditions. Damage in the small intestine underlies many immune and autoimmune conditions, food reactivity, and nutrient malabsorption.
There are a variety of food and lifestyle factors that contribute to supporting a healthy, intact gut barrier. Flavonoids are components present in plants that have been proven to benefit the gut lining. They’re abundant in most vegetables, fruits, green and black tea, red wine, chocolate and coffee. Vitamins, minerals and trace elements from foods (specifically vitamin D, vitamin A and zinc) have been associated with the regulation of the intestinal barrier, as well. Glutamine, an amino acid, supports the integrity of the gut barrier, the microbiome and also modulates inflammatory responses. Glutamine is found in protein rich foods, especially animal sources like chicken, beef, eggs, poultry, and bone broths. Plant sources of glutamine are present in nuts, beans and even raw cabbage.
In addition to quality, nutrient dense foods, exercise also enhances the bacterial population in your gut. Even different types of exercise promote different types of bacteria. High intensity training has been shown to increase bacteria associated with leaner body composition while steady state endurance training increases bacterial populations associated with increased fat storage. This makes perfect sense, since fat is used as an energy source during long bouts of aerobic exercise.
Some of the most damaging foods to the mucosal barrier and microbiome are highly processed foods, which contain industrial food additives. Emulsifiers, which are used to keep ingredients from separating in foods and beverages, directly thin the mucous barrier. This increases the contact of toxic material with your bloodstream, enhances inflammation and can create immune dysfunction. On an ingredient label, examples of emulsifiers are polysorbate 80, lecithin, carrageenan, polyglycerols, and xanthan and other “gums.” They’re present in “healthy” items, too, like many non-dairy milk substitutes.
Another ingredient to avoid is artificial sweeteners of any kind. Non-caloric sweeteners are abundant in diet foods to keep the calorie content low, but ironically, the damage they do to your gut can alter the way your body metabolizes food and potentially leads to increases in body fat. Sucralose (in Splenda), saccharine, aspartame, and sugar alcohols (like erythritol and xylitol) have all been clinically shown to increase inflammatory markers in the gut and disrupt the balance and diversity of the gut’s microbiome. Even stevia, which is a naturally occurring herbal non-caloric sweetener has been shown to disrupt gut balance. Monk fruit is another naturally occurring non-caloric sweetener that is relatively new to the market, but no studies have been done yet on its impact to the gut. On the other hand, small amounts of raw honey and pure maple syrup can support a healthy gut environment. Raw honey contains nondigestible oligosaccharides that feed beneficial bacteria and substances that kill pathogenic strains. Pure maple syrup contains polyphenols that have a positive effect on microbiome diversity. When it comes to satisfying your sweet tooth, your healthiest bet is to include raw and organic honey and maple syrup in small amounts.
Other factors known to damage or disrupt gut health include alcohol, medications, and stress. Sure, red wine does contain flavonoids which support the gut lining, but the alcohol itself is a toxin that damages the gut lining and increases permeability and inflammation. Various over the counter and prescription medications have been shown in studies to be a key modulator of the gut microbiome composition. Non-steroidal anti-inflammatories (like ibuprofen, aspirin, and naproxen) and proton pump inhibitors (like Prilosec, Nexium, and Prevacid) are some of the most commonly used medications that create imbalances in the gut.
If your goals this year include improving your health and/ or body composition, perhaps optimizing your gut health should be your main focus. Prioritize food quality rather than food or calorie quantity. Avoid highly processed foods and include a large variety of fresh, organic foods to promote a wide variety of healthy gut microorganisms. Be sure to consume plenty of fiber, which feeds your gut population, and avoid produce sprayed with pesticides and herbicides, and animal products treated with antibiotics. Additionally, regularly perform a variety of exercise, and spend time in nature soaking up vitamin D from the sun and microbes from the soil. Don’t be afraid to get dirty!
There is no simple pill or restrictive diet that can provide a quick fix when it comes to your wellness. Take care to support the community of microorganisms that live within you, and they will do their part to support your health in return.