The immune system is complex. Even researchers currently have only a topical understanding of the relationship between gut microbiota and immune system function, but what they have already discovered has changed the way doctors and scientists think about immunity. As the scientific understanding of this specialized field advances, it becomes increasingly clear that achieving optimal immunity requires maintaining a healthy gut microbiome.
The Home of the Immune System
Around 80% of the immune system can be found in the GI tract.1 Gut bacteria don't just affect digestion. They also maintain immune homeostasis, ensuring that the immune system can identify and eradicate pathogens without turning on the body's healthy cells to cause autoimmune disorders.
Learning that the vast majority of immune responses originate in the gut can be quite empowering. Those willing to put in the effort to keep their gut microbiomes healthy can take control over their immune systems and reduce their chances of becoming ill. A healthy community of gut bacteria can help to protect their hosts against everything from cancer to the common cold and more serious viral infections.
Understanding the relationship between gut bacteria and human health requires acknowledging the role of evolution. All mammals are hosts to diverse communities of bacteria, which have co-evolved with them across the millennia, and people are no exception.
A Complex Relationship
Part of what makes the relationship between gut bacteria and the immune system so complicated is that while the immune system is a part of the human body, gut microbiota technically live outside the body. Despite this disconnect, the two systems interact.
Professor of pathology Dan Peterson studies these interactions at the Johns Hopkins University School of Medicine. He points out that the lining of the human GI tract has evolved to contain cells whose only apparent purpose is to excrete antibodies into the gut. These antibodies, he believes, constitute an example of the body trying to control how it interacts with gut bacteria.2
Peterson and his team have not yet uncovered the exact biological mechanisms that mediate these interactions, nor do they know exactly what type of antibodies are being produced. Peterson's current research focuses primarily on autoimmune disorders like inflammatory bowel disease (IBD) and colitis, which he believes may be caused by abnormal immune responses to otherwise innocuous gut bacteria. However, additional research has shown that a healthy relationship between the body and the gut microbiome can act as a protective mechanism against many other diseases.
The Role of Lifestyle in Maintaining a Healthy Gut Microbiome
Eating healthy foods is one of the best things people can do to support their immune systems. Just like we need certain vitamins, minerals, and nutrients to live, beneficial bacteria have certain environmental and nutritional requirements that must be met.
We can help to support their gut microbiota by following healthy diets rich in fruits and vegetables and low in sugar and processed foods. However, diet isn't the only factor that impacts the gut microbiome. Chronic stress and lack of exercise can also throw bacterial communities out of balance and contribute to immune dysfunction.
Positive changes in our diets have been shown to boost the immune system by improving the health of the gut microbiome. Since these bacteria co-evolved with people for millennia, they're programmed to thrive when exposed to foods like fruits, vegetables, legumes, and ancient grains. Beneficial bacteria need carbohydrates like those found in dietary fiber to thrive. Thankfully, these are the same foods that people need to support healthy immune function on their ends. Fruits and vegetables are packed with antioxidants, known to reduce the proliferation of free radicals, which cause cancer and other serious diseases. Try to include fruits and veggies that span the entire color palette and opt for ancient grains or whole grains instead of processed foods.
It's also best to avoid consuming excessive amounts of dietary fat and fructose. These foods disturb the GI barrier and feed harmful bacteria that use these substances to produce toxins damaging to human health.3 Try to avoid red meat and processed foods high in sugar and fat to cut off the supply chain to harmful, toxin-producing bacteria.
Exercise is a great way to boost the immune system. Just half an hour per day of moderate-intensity exercise can protect against both mild illnesses and severe, chronic diseases by reducing inflammation and enhancing antioxidant defenses. According to recent research, it can also shift the composition of gut microbiota.
Scientists have only recently begun to research the connection between physical activity and the gut microbiome. In 2016, researcher Sara Campbell published an animal study that showed clear benefits to physical exercise in the gut microbiomes of lab mice.4 Her research showed that mice that got plenty of exercise had higher concentrations of the beneficial bacteria Faecalibacterium, Clostridium, and Allobaculum in their guts than mice that did not exercise. These results were the same independent of diet.
A second human study published in 2018 provided similar insight. After exercising for six weeks, participants developed elevated levels of Clostridiales, Lachnospira, Roseburia, and Faecalibacterium, all of which produce a short-chain fatty acid known as butyrate. This fatty acid has been shown to play a beneficial role in cell proliferation, which helps to maintain optimal health and immunity.
Campbell and other researchers in her field have identified several potential biological mechanisms that may be at play. First, exercise raises body temperature and reduces blood flow to people's intestines. This creates more direct contact between the immune cells found in the walls of the digestive tract and the beneficial bacteria that support immune function. Exercise also increases the circulation of bile, which leads to shifts in pH and subsequent changes in gut microbial communities. Physical activity may also change the composition of participants' gut mucus, creating a more beneficial environment for bacteria like Akermansia municiphila responsible for creating anti-inflammatory effects.5
Chronic stress has long been acknowledged as a contributing factor to immune deficiencies. It's only within the past few years that researchers have uncovered a direct connection between stress and the gut microbiome, but new research into how social stress alters the composition of gut bacteria in mice has provided some insight into the biological mechanisms behind the negative impacts of stress.
When researcher Michal Werbner and his colleagues exposed a group of mice to daily stressful encounters for ten days, they found that it changed the composition and behavior of the bacteria biophilia and dehalobacterium.6 These bacteria have already been linked to autoimmune disorders in humans. In mice exposed to the experimental conditions of daily stress, populations of these bacteria increased growth, movement, and communication with the host mice, traveling throughout their bodies and infecting healthy tissues.
Although the researchers focused on autoimmune disorders, in which the body's immune cells mistake healthy tissue for pathogens and attack it, chronic stress has also been shown to reduce immune system response in otherwise healthy individuals. There's no way to eliminate stress from modern lifestyles completely, but that doesn't mean we are helpless to prevent these problems. Stress reduction techniques like meditation, deep breathing, engaging in physical activity, and maintaining positive social connections have all been proven to improve immune response.
Herbs and Supplements
Reducing stress, getting plenty of exercise, and maintaining a healthy diet can go a long way toward boosting the immune system and ensuring the health of beneficial gut bacteria, but these steps aren't always enough. During uniquely stressful situations or at times when we are at high risk of becoming ill, it makes sense to provide the gut microbiome with some extra support. Here are a few of the best supplements for maintaining optimal immunity and healthy gut microbiota:
NuMedica Tri-Flora Plus
NuMedica's Tri-Flora Plus supplement contains beneficial probiotics, which support the gut bacteria responsible for breaking down food and ensuring healthy immune responses. Sometimes we only take probiotics after being prescribed anti-biotic medications, but that's a mistake. It's best to take pro-biotics every day to reduce the chances of getting sick, to begin with.
NuMedica ImmunoG PRP Powder
ImmunoG PRP Powder is formulated to heal human tissue and restore balance to the gut microbiome. It's full of proline-rich polypeptides (PRPs), which have been shown to bind to receptors on immune cells to assist with immune modulation. The PRPs stimulate white blood cell production in the presence of pathogens, then regulate the immune response to soothe leftover inflammation after the infection has subsided. PRPs have also been shown to increase bone mass and lean muscle mass.
NuMedica Alpha Lipoic Acid
Alpha Lipoic Acid is a naturally occurring nutrient found primarily in green, leafy vegetables. It permeates cells to eliminate free radicals, stabilizes blood sugar, and, since it's fat- and water-soluble, it can even cross the blood-brain barrier to act as a protective agent against dementia. Combining Alpha Lipoic Acid with pro-biotics and PRPs provides us with a full range of tools to boost immunity and reduce their chances of getting sick.
NuMedica ImmunoMed 3-6
This powerful immune modulator contains Beta-glucans, a substance derived from yeast and found in certain plants and known to help the immune system fight off infections. Beta-glucans have also been shown to lower our risks of infection after surgery or acute trauma. Although they can be found in certain foods, including oats, barley, and some mushrooms, beta-glucans supplements are more concentrated for maximum effectiveness.
Signs of an Unhealthy Gut Microbiome
While it's fairly obvious when patients have severe autoimmune disorders, some may not always recognize when their immune systems aren't functioning at optimal levels as a result of gut microbiome imbalances. We don't need to wait until we get sick to recognize that there's something wrong. Instead, we can keep an eye out for the common signs of potentially dangerous microbiota imbalances.7
Scientists have been aware of the connection between gut bacteria and digestion for far longer than they have studied the gut microbiome's role in immune responses. The same imbalances that cause immune system inefficiencies can also cause digestive symptoms, which are much easier to recognize. Problems like bloating, excessive gas, constipation, and diarrhea can all be symptoms of an unbalanced gut microbiome.
Unintentional Weight Changes
Imbalanced gut microbiota can impair the body's ability to absorb nutrients. It can also cause problems with regulating blood sugar and storing fat. Unintentional weight loss is often caused by an overgrowth of small intestinal bacteria. Unintentional weight gain may be the result of overeating in response to decreased nutrient absorption due to a lack of healthy bacteria.
The majority of hormones that affect sleep and mood are produced in the gut, and an imbalance in microbiota can contribute to hormone dysregulation. This may cause sleep disturbances, including insomnia, which often lead to chronic fatigue. It may also cause unexplained mood changes.
Food intolerances are different from allergies. When we have allergic reactions to certain foods, they occur as a result of an inappropriate immune system reaction. Intolerances are caused by imbalanced gut microbiota. In other words, the bacteria required to break down and digest certain foods may not be present in sufficient quantities, which leads to digestive upset and abdominal pain.
The Bottom Line
The first step toward boosting immunity is to understand that there is a connection between the immune system and the gut microbiome. The second step is to recognize potential microbiota imbalances before they become so severe that they leave us prone to developing serious diseases.
Instead of waiting to get sick, we can take high-quality, professional-grade nutritional supplements from NuMedica to encourage the growth of healthy bacteria, decrease free radicals, and give their immune systems a healthy boost. Start taking advantage of natural methods for improving immune response and decreasing the risk of contracting serious diseases.
Citations:1 Furness, J.B., Kunze, W.A., & Clerc, N. (1999). Nutrient tasting and signaling mechanisms in the gut. American Journal of Physiology, 277(5): G922-8.
2 Fields, H. (2015). The gut: Where bacteria and immune system meet. Johns Hopkins Medicine Research.
3 Li, J.M., Yu, R., Zhang, L.P., Wen, S.Y., Wang, S.J....Kong, D. (2019). Dietary fructose-induced gut dysbiosis promotes mouse hippocampal neuroinflammation: a benefit of short-chain fatty acids. Microbiome, 7(98).
4 Campbell, S., Wisniewsi, P. J., Noji, M., McGuinness, L. R., Haggb lom, M. M....Kerhof, L. J. (2016). The effect of diet and exercise on intestinal integrity and microbial diversity in mice. PloS One, 11(3): e0150502.
5 Monda, V., Villano, I., Messina, A., Valenzano, A. Esposito, T....Messina, G. (2017). Exercise modifies the gut microbiota with positive health effects. Oxidative Medicine and Cellular Longevity, 3831072.
6 Werbner, M., Werbner, N., Barsheshet, Y., Zingdon, O., Averbuch, I....Avni, O. (2019). Social-stress-responsive microbiota induces stimulation or self-reactive effector T helper cells. Msystems, 4. 7 Dix, M. (2018). What's an unhealthy gut? How gut health affects you. Healthline.