Where Immunity Begins + How To Boost It

While many of us hoped for a back-to-school season free from COVID concerns, the reality is the virus is still lingering and with breakthrough cases and the rise of the Delta variant (and others), immunity is back to the forefront of our minds. And it’s not just COVID, either. Going back to the classroom or office means facing all types of germs, including the seasonal flu, the SARS-CoV-2 virus variants, and various bacteria that can cause anything from strep to staph. 

I know many of you are frustrated and disappointed that COVID isn’t in the rearview mirror by now. I get it! We’re living in some pretty crazy times. All we can do is stay calm, and of course, focus on the one thing that can make us resilient in the face of any infection — improving the health of our immune system from it’s very core, which just so happens to be the gut.

Why Immunity Begins in the Gut

The belief that immunity begins in the gut used to be considered “fringe” or “woo-woo.” But in recent years, it’s gone fully mainstream. Take a recent study , for example. Published in the British Medical Journal , the study analyzed the gut microbiome of 100 patients with a positive COVID diagnosis by collecting blood and stool samples. The results showed that although Covid-19 is primarily a respiratory illness, there is strong evidence the GI tract is involved in the disease. More specifically, the patients with more severe cases of COVID-19 had a different gut microbiome makeup than those with more mild cases of COVID-19. For example: Patients with severe disease had elevated concentrations of inflammatory cytokines like C-reactive protein and lower levels of beneficial gut bacteria that help reduce inflammation, like Faecalibacterium prausnitzii , Eubacterium rectale and Bifidobacteria . 

This study is just one relevant example of how when it comes to immune threats, having a diverse, plentiful, anti-inflammatory community of gut bacteria is key. And it’s not just external immune threats from an outside invader like a virus or bacteria, either. The gut is also key to preventing autoimmune conditions, too. Autoimmune disease occurs when your body loses the ability to distinguish between outside invaders and it’s own tissue; as a result, your immune system starts attacking your body’s tissues by accident. 

Studies show that the gut microbiota play a “crucial role” in autoimmune disease, especially those that occur in the gut, such as Crohns’s and ulcerative colitis. The authors of one study even wrote that “The gut microbiota maintains the homeostasis of our immune system.” But how does this work, exactly? The authors of the same study wrote that there are several mechanisms at play here, including the gut’s ability to affect the functioning of antigen-presenting cells (white blood cells that present foreign proteins to our B and T cells to develop an advanced immune response), dendritic cells, and the activity of inflammatory cytokines and T cells, which are key to the intelligence and accuracy of the immune system. In the not-so-distant future, I feel confident saying that the gut microbiome will be a key target for the treatment of autoimmune disease. 

So, if the gut is so key to our immune system, then how do we support it? One of the best places to start is eating a gut-friendly diet free from common gut-disruptors like added sugar, processed dairy and meat, excess alcohol, and inflammatory grains, like the refined white flour found in most packaged foods, like crackers and cookies. 

Beyond that, there are a ton of ways to fortify your gut to take your immune health to the next level.