Dr. Emeran Mayer

Learn how your gut and your immune system are connected

70% of our immune system lives inside our gut (the GI tract specifically), which means what you feed your body can have long term effects on how you feel. 


August 1, 2022

Written by:

Medically Reviewed by:

Dr. Emeran Mayer


May 2, 2024

Mind-Gut Connection
Mind-Gut Connection

If you’re a Salvo Health member or subscribed to The Salve, our recurring newsletter, there’s a chance you’ve heard of the mind-gut connection or the gut-brain connection. However, as focus on the informational highway between the brain and your digestive system, we sometimes neglect to focus on the fact that your gut health has an impact on many systems in your body including your immune system. In fact 70% of our immune system lives inside our gut (the GI tract specifically), which means what you feed your body can have long term effects on how you feel. 

How is the gut connected to our immune system?

When we say that the immune system lives in the gut, what we mean is that immune cells in the lining of our gut constantly interact with the gut microbiota, the bacteria, fungi and other microorganisms inside the gastrointestinal tract. The gut microbiome is directly influenced by what we eat, and what we put inside our can also affect the gut’s immune system. 

Salvo Health’s Clinical Advisory Board Member Dr. Emeran Mayer defines the interplay between the gut and the immune system: “Specialized cells within your immune system have extensions that reach into the gut. Receptors on these extensions respond to cell wall components of gram negative bacteria. So your immune system is constantly monitoring the presence of gut microbes, not just when you have a gut infection. Even when a benevolent microbe comes in touch with those receptors, your gut can trigger an alarm bell in the immune system, often with consequences throughout the body.”

The gut microbiota modulate the immune system’s response to unhealthy food and harmful entities in the gut.  In the case of harmful stimuli, the immune system triggers the release of molecules and antibodies to protect our body against foreign or harmful bacteria. 

Because of its close interconnectivity, many GI specialists and gastroenterologists have speculated how the gut can likely weaken the immune system, or the negative effects the two can have on one another, leading to the Leaky Gut Syndrome theory.

What is leaky gut syndrome? 

Stick with us because we know that Leaky Gut Syndrome sounds kind of scary. Symptoms can include diarrhea, constipation, or bloating, but also nutritional deficiencies, fatigue, headaches, skin problems, even joint pain. So again, nothing fun, but nothing too new if you already have a chronic gut condition and are looking for a reason for your diagnosis.  

Salvo Health Clinical Advisory Board Member Dr. Frank Lipman describes how Leaky Gut Syndrome occurs: “The gut lining is particularly thin, and it can be damaged by an altered microbiome or certain foods and their byproducts. The damage can lead to the leaking of byproducts of food breakdown or metabolites from bacteria through the gut wall and into the bloodstream, which then can trigger an inflammatory response from the immune system.”

Keep in mind, Leaky Gut Syndrome is a hypothetical condition that occurs to the intestinal wall or gut lining, rather than an official diagnosis like IBS or GERD. Meaning some doctors believe that leaky gut could be a reason for one’s chronic GI condition, while others believe that leaky gut is a consequence of other chronic gut conditions, not a condition or a cause on its own.  The relationship between the intestinal wall and the rest of our body, and whether or not it can be damaged, isn’t entirely clear. 

So today’s top researchers and gastro doctors remain divided on Leaky Gut syndrome, including members of the Salvo Health Clinical Advisory Board. Dr. Emeran Mayer believes that the symptoms of Leaky Gut are not because of a compromised gut lining, but just caused by the immune system’s activation in the gut. “The concept of “Leaky Gut” assumes that there is a firewall between healthy gut microbes and the immune system, and that this firewall can be compromised. There's multiple mechanisms by which the immune system and its relationship to the gut can be compromised, even on a molecular basis. So I think the low grade immune activation is more of a pathophysiological factor, that doesn't require actual translocation of microbes or food components across the gut barrier.” 

How can I keep my gut and the rest of me healthy? 

One thing’s for certain, if your immune system is triggered by influences from unhealthy food or signals from an unhealthy gut microbial ecosystem, it could cause some unpleasant symptoms for you. It’s probably the reason it feels like your body is waging war whenever you eat mac n’ cheese. So how do you help keep the communication between  your gut and your immune system peaceful? Well, you feed your gut bacteria what it needs. 

As Dr. Mayer says, “If you can create a highly diverse gut microbiome, you can not only optimize your bowel movements, but increase the production of your own anti-inflammatory molecules.”  

Take these pieces of advice when you’re deciding on what to eat for your overall health: 

  • Eat a diverse array of veggies as the main source of fiber: Dr. Mayer likes to eat large salads on a regular basis, “loaded with fifteen different types of vegetables” and topped with a piece of protein, like the aforementioned fatty fish, like salmon. Spinach and red bell pepper are both IBS-friendly and good for your immune system. 
  • Eat protein regularly, not just at dinner: A serving of protein for every meal, or regularly throughout the day, is a good rule of thumb. There are many plant based sources of protein, such as beans, peas and other legumes, 
  • Load up on healthy fats, while reducing bad fats such as those contained in many meat products: We’re talking avocados, nuts, seeds, olive oil, and fatty fish like salmon. 
  • Polyphenols can’t hurt, like those found in gut-friendly blueberries, cocoa, or green tea.
  • Diversify your gut microbiome with fermented foods like kefir,  kimchi, Sauerkraut or Kombucha which have been shown to increase the diversity of your gut microbiota.  
  • Avoid eating foods that you know trigger your symptoms, including lactose (most adults are lactase deficient) and certain vegetables, but remember everyone’s gut is different, so it’s important to be absolutely certain of which foods trigger your gut symptoms, before eliminating things that are healthy, and that you love from your routine . 

How Salvo Health can help you protect your gut and immune system 

Salvo Health is helping the 60 million Americans living with chronic gut conditions by providing continuous, comprehensive healthcare through our virtual clinics. We specialize in helping our members figure out the root causes of their gastro conditions, connecting them with a doctor instantly through our messaging app. 

Their Care Team, including a dedicated doctor and board-certified Health Coach, can get them connected to the right testing, diagnostics, as well as identify what lifestyle changes a member needs to make, transforming nutrition, movement, sleep routines to minimize stress and optimize gut health. 

If you’re interested in improving your gut health for good, and also boosting your immune system at the same time, take our assessment to get started.

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