All You Need to Know: How a Healthy Gut Boosts the Immune System


Our gastrointestinal tract (GI tract) is packed with trillions of beneficial bacteria that make up our microbiomes. The gut microbiome is the community of bacteria and other microorganisms living in and on us that works to keep our bodies running efficiently. A healthy microbiome is key for digestion, metabolism, blood sugar balance, and of course, our body’s first line of defense—the immune system. 

The immune-gut connection

The gut and the immune system are completely intertwined. We are constantly exposed to many types of bacteria and microorganisms, and eventually develop an ‘immune tolerance.’ This means our immune system can start to differentiate the good bacteria from the harmful bacteria. A strong immune tolerance stems from a healthy gut and is essential to ensure that an immune-induced inflammatory response is set off only when necessary. Our gut health is influenced by the balance of gut flora and, therefore, the balance of the immune system. The tissue in our gut, known as GALT tissue (gut-associated lymphoid tissue), is involved in direct communication with the immune system and the production of antibodies required to fight off infections. 

Why gut health is so important for our immune system

The foundation of a healthy gut is built through a quality diet, one that provides a diverse range of bacteria from fiber-rich and fermented foods. The greater the diversity of the bacteria population in the gut, the greater the ability for the microbiome to work more efficiently in order to regulate an effective immune response. F45 Nutritionist Kim Bowman mentions that one of the simplest ways to begin prioritizing gut health is to “avoid refined sugars and processed foods, which are highly inflammatory and can disrupt the microbiome over time. This disruption can lead to ‘leaky gut syndrome,’ an inflammatory state within the body that results from an unbalanced or lack of healthy bacteria that would normally support proper gut lining.” A weakened gut lining can result in harmful bacteria leaking through the intestinal wall and into the bloodstream, causing inflammation. 

What We Can Do to Sustain a Healthy Gut

Prebiotics and probiotics

Both prebiotics and probiotics are essential for gut health. Probiotics—commonly found in yogurt, kefir, and tempeh—are the beneficial bacteria in our GI tract and are essential for the gut microbiome and immune system to work efficiently together. Prebiotics differ from probiotics in that they aren’t bacteria, but instead act as food for our gut bacteria to thrive and continue supporting the immune system. Vegetables and fruits—especially bananas, asparagus, broccoli, and garlic—are rich in fiber and provide quality nutrients for our gut. 


Healthy gut bacteria are able to produce a strong gut barrier that prevents foreign microorganisms from causing inflammation within the body. Daily consumption of foods that support our gut microbiome, as well as probiotic supplementation, create a healthy, diverse population of gut microbiota and a stronger gut lining as a result. 

Intermittent fasting 

Intermittent fasting is a mindful eating pattern that consists of cycling through periods of fasting and eating. The most common protocols are the 14:10 or 16:8 methods, which involve eating within an 8-10 hour period (i.e. 10am to 6pm) while fasting for 14-16 hours (i.e. 6pm to 10am the next day). Research has highlighted that sticking to a consistent eating pattern each day through intermittent fasting may help us avoid snacking late at night. As a result, our bodies are not only able to metabolize more efficiently, but also regenerate new cells in the immune system. 

Gut-friendly foods 

  • Bone broth
  • Organic plain Greek yogurt
  • Fermented foods (i.e. kefir, sauerkraut, miso, kimchi)
  • Garlic
  • Almonds 
  • Olive oil


Our gut and immune system are largely intertwined; therefore, it’s essential to be proactive with gut health to ensure our immune system can function at its best. Aside from probiotics, prebiotics, and a quality diet, regular activity and stress management through yoga and meditation are important to optimize gut health. 


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