While you may typically think of microorganisms as something to get rid of (hello hand sanitizer!), those microbes are actually crucial to your health and well-being. Not only do they play a role in digestion, they also help us develop immunity, protect us from allergic disease and bad bacteria and may even influence our brain and behavior. That’s a lot of work for some tiny critters!
What else do you need to know about your microbiome for optimal health? Here are five key facts from my new book co-authored with Jonathan Galland, The Allergy Solution: Unlocking the Surprising, Hidden Truth About Why You Are Sick and How To Get Well:
1. Just like a fingerprint, everyone's microbiome is unique.
Your microbiome consists of 10 to 100 trillion microbes primarily in your gut. From before birth, we’re colonized by an army of microbes—bacteria, yeast and even viruses. It helps to create a protective barrier that defends your body against foreign substances and allergens. Your gut microbiome reacts to the world around and within you, and as a result, your microbiome is unique and distinct, like a fingerprint.
2. You have to cultivate your gut flora.
Your gut microbiome is a dynamic, living thing that needs to be tended to, just like a garden. Cultivate your good microbes with a nutritious, varied whole food diet rich in fruits and vegetables and fermented foods. Fiber and other complex carbohydrates like resistant starch (think bananas, plantains, beans and sweet potatoes) aren’t absorbed or digested in your gut. Instead, they travel through the small and large intestines and encourage the growth of beneficial bacterial flora.
And go organic when you can. Since organic farming preserves the diversity of bacteria in the soil, it also preserves it in the food you eat.
3. What happens in your gut doesn't stay in your gut.
While you might associate your gut only with digestion of food and absorption of nutrients, it does a lot more than that. Most importantly, it’s the largest organ of the immune system with over two-thirds of our lymphocytes found in the lining of the small intestine. Thus, the health of our gut impacts our nutrition, allergy, skin, immune response, metabolism, sleep and mood.
For example, researchers from Washington University School of Medicine found that participants’ microbial community changed as their body weight decreased, to resemble a “lean” person’s microbiome. Scientists from Washington University also found that the gut microbiome is a factor in fat storage.
Plus, Dutch researchers have found that people who regularly have GI troubles tend to have a higher prevalence of migraines.
3. There's a connection between your gut, and allergy and immunity.
Allergies start in your gut. The problem arises when your gut becomes “leaky": thanks to the depletion of beneficial intestinal microbes, your gut becomes more permeable and absorbs more gut-derived toxins and food-derived allergens than normal, which can lead to allergic sensitization to food protein, as well as conditions like inflammatory bowel disease. When you ingest those allergens again, it leads to a vicious cycle that further inflames the intestinal lining.
For example, Swedish researchers followed children from birth to age five and found that the absence of certain bacteria preceded the development of allergic disorders. And new research suggests that fixing the gut can help prevent the development of eczema and reduce the severity of symptoms associated with allergic rhinitis and asthma.
4. There are three big offenders that can harm your gut.
Three main culprits cause the most damage to your microbiome—medication, infections and foods:
• Medication, particularly NSAIDS like aspirin, ibuprofen and naproxen-type pain relievers, have been shown to reduce levels of good bacteria in your GI tract, thus increasing intestinal permeability. Overuse of antibiotics—both the medicine you take and that’s given to the animals you eat—can also decrease the diversity of our gut flora.
• Infections can create inflammation in the gut, which can also make the intestinal wall leaky.
• The food you eat can lead to inflammation in the GI tract too. A diet high in sugar and saturated fat creates a state of systemic inflammation. In a 2015 study, researchers found that alcohol-induced changes to the microbiome may contribute to intestinal hyerpermeability and oxidative stress as well as intestinal and systematic inflammation. Plus, if you eat food that you’re allergic to, your gut will also become inflammed and leaky.
5. You can reestablish healthy gut flora.
There are three primary steps to reestablishing healthy gut flora. First, avoid exposure to those major gut offenders mentioned above.
Next, create an environment that allows good gut flora to flourish. For some, probiotics—which can be taken as food, such as fermented foods, or supplements—may help. In one study, Italian physicians gave a probiotic (Lactobacillus GG) to participants with abdominal pain for eight weeks. Intestinal permeability improved and pain was significantly reduced, compared to a placebo. In another study, Finish scientists found that the same probiotic strain decreased intestinal inflammation and eczema in participants with eczema caused by food allergy.
Lastly, cultivate your good microbes with a nutritious, varied whole food diet rich in fruits and vegetables.
Scientists are just scratching the surface on all the different areas of our bodies that our microbiome influences. There’s still a lot to be learned!