Bacteria = Friends + Food
We've spent years trying to be "germ-free," but did you know that our bodies are made up of more microbial cells than human cells?
Despite their dirty reputation, bacteria are essential to a healthy lifestyle, because they aide in various biological functions that human body cells alone would not be able to successfully accomplish. Up until recent years, we adopted the so-called clean practices of the “hygiene hypothesis,” by which we sought to eliminate all bacteria and other microbes, under the impression that antiseptic living equates to healthy living. We now know that this is not true, as microbes work synergistically with our own human body cells to optimize our biological functions.
One of the most important roles of these bacteria is in food digestion; the appropriate bacterial population in the digestive tract benefits the body as a whole. Unfortunately, modern medicine has prevented many people from achieving an optimal gut microbiome, thus leading to a wide array of biological imbalances and health complications. Namely, we see a rise in food allergies and sensitivities with the increased use of antimicrobial agents present in our medical treatments, food, household items, etc. Choosing to adopt a proactive lifestyle in improving gut health would serve advantageously to our overall health and well-being.
Let’s discuss the importance of maintaining a healthy gastrointestinal (GI) tract in general. The barrier between our intestinal tract and the immune system is extremely thin, therefore if this GI lining is compromised, unwanted particles may enter and activate the immune system to induce an unnecessary inflammatory response. In an ideal world, our bodies are exposed to the necessary microbes early in life, and continue to develop an apt gut microbiome that protects us from such inflammatory issues. The microbes in our digestive tract help us maintain a healthy GI tract and strong lining to prevent a leaky gut.
Our gut microbiota is also responsible for helping us digest many foods, thus the lack of a diverse bacterial population may lead to food allergy and/or intolerance. These bacteria help us digest fiber into short-chain fatty acids (SCFAs), which stimulates the dendritic cells of the immune system to control the body’s responses towards food allergens. High levels of SCFAs will encourage the dendritic cells to suppress the allergic response altogether. However, when certain foods enter a digestive system that lacks the appropriate bacteria, the body’s immune system recognizes the chemicals in these foods as foreign invaders, thus prompting an immune response and leading to a variety of symptoms.
Research indicates that certain gut microbes can influence our bodies' reactions to some food allergies. The most common food allergy is that towards peanuts, and studies have shown that a peanut allergy may develop following oral antibiotic treatment that often depletes the microbial population in the GI tract. Moreover, this eradication of the microbiome may also lead to food intolerance as well—specifically towards cow’s milk products, a food product to which many people are intolerant. Fortunately, recolonization of a damaged microbiome could at least partially restore the gut health and suppress the immune responses induced by food allergy and/or intolerance. For instance, gut colonization of certain Clostridia species sufficiently reduces sensitization and symptoms of the peanut allergy.
There are multiple ways in which one can restore a depleted gut microbiome, and in turn improve overall health. For one, you should consult with a healthcare professional to determine which foods to discontinue eating if you test positive for an allergy/intolerance towards certain food items. Any attempt to restore gut health without eliminating the gut-damaging factors would prove futile. The most common food intolerances are those to gluten, dairy, and sugar, therefore your nutritionist may strongly advise to you eliminate such foods from your diet as you work to restore and maintain a healthy digestive tract.
In addition to using probiotics that contain such beneficial microbes, the use of prebiotics is now emerging as another method to maintain healthy gut bacteria and suppress food intolerance. While probiotics refer to the bacterial species we need, prebiotics are the food sources of such probiotics. As previously mentioned, fiber is a prime food source that helps the human body control the immune response towards food allergens. Even though human body cells alone are unable to digest fiber, it is the vital prebiotic in promoting growth of the beneficial intestinal bacteria that can digest it. Unsurprisingly, studies have shown that increased fiber consumption and dietary vitamin A is associated with milk intolerance resolution.
You can also work to prevent further gut damage by avoiding antibiotic use, if suggested by your physician. Limiting antibiotic usage in children is especially important because development of their gut microbiota occurs in the early years of life. In fact, bacterial exposure occurs immediately at birth, which is why the type of delivery (i.e. vaginal vs. caesarean section) helps dictate one’s health. As newborns progress throughout their childhood years, their environmental factors play essential roles in maintaining a healthy gut microbiome. These factors include: breastfeeding, attending childcare early, growing up with siblings, raising pets, etc. Exposure to certain microbes during this developmental period is crucial for building a strong and resilient immune system because gut health is correlated with general immune health, therefore disruption of the microbiome development could lead to food allergy and/or food intolerance.
I cannot stress enough the importance of maintaining a healthy gut lining at every stage of life. I mean, the immune system lies right underneath it! If you don't know where to start or are overwhelmed with all the information out there on the web, fill out the contact form and let’s start chatting!
Blazquez AB and Berin MC. 2017. Microbiome and food allergy. Translational Research. 179:199-203.
