How to Heal Your Gut for a Stronger Immune System (Part 1 of 2)

When you think of staying healthy and supporting your immune system, what’s the first thing that comes to mind? Washing your hands? Avoiding germs? Maybe taking lots of vitamin C? These approaches might help ward off illness, but do you want to know the real secret to a stronger and healthier immune system? It’s in your gut.

I. Your Gut & Your Immune System

Your immune system is a complex network of cells, tissues, organs, and signaling molecules that all work together to defend against perceived threats. Your gut and immune system are more intricately connected than researchers thought even 10 years ago! Here are some ways your gut supports your immune system: 1,2

  • Immunity: Your gut houses a large number of immune cells in what’s known as gut-associated lymphoid tissue (aka, GALT). In fact, 70-80 percent of your immune system is found in these gut tissues.
  • A Blocking Barrier: The epithelial cells lining your intestines link together forming a barrier that blocks harmful pathogens from entering the rest of your body and causing damage.
  • Bacteria Trapping: The cells that line your digestive tract are coated with mucins and glycoproteins that trap, neutralize and excrete harmful bacteria.
  • Sensors: Your intestinal cells act as sensors – sounding the alarm and recruiting immune cells to destroy foreign invaders.
  • Communication: Your immune system and the millions of beneficial bacteria in your gut communicate crucial information to each other.
  • Supporting Metabolism: The beneficial bacteria residing in your gut produce short-chain fatty acids and other compounds to boost immunity, reduce inflammation, and support metabolic functions.  

If your gut develops dysbiosis or intestinal permeability, commonly called leaky gut, then your immune system will be thrown out of whack. So what are: A. Dysbiosis and B. Leaky Gut?

A: Dysbiosis

Your body’s microbiome is a cocktail of diverse organisms with thousands of different microbes performing different functions. The goal of your microbiome is to maintain homeostasis. When in homeostasis, a healthy balance of beneficial microorganisms do their jobs while bad bacteria get flagged and removed before they can replicate. So what happens when this delicate ecosystem becomes imbalanced? It will throw your immune system out of whack.

An imbalanced microbiome is known as dysbiosis. Dysbiosis occurs when invading microorganisms populate your gut and crowd out your “good” bacteria.3 This interferes with your gut’s ability to properly communicate and coordinate with your immune system. Worse yet, dysbiosis can cause your immune system to become overworked and hypervigilant – leading your body to mistakenly begin attacking its own cells. This is known as autoimmunity.   

B: Leaky Gut

Your intestinal lining covers more than 4,000 square feet of surface area. It’s constantly bombarded with toxins and foreign pathogens from whatever you ingest.4 Because of its large surface area and constant exposure to both good and bad microbes, our digestive tract is designed to be the ultimate barrier. It lets good nutrients through to your bloodstream while keeping harmful compounds locked up tight until they can be excreted. It accomplishes this with a thin layer of cells lining the inside of your intestines; these cells are linked together by proteins called tight junctions and act as a “filter.”5 

If these tight junctions become compromised, those “gaps” in your “filter” allowing nutrients to pass through get bigger and bigger and bigger — we call this a leaky gut. A leaky gut allows tiny particles never meant to enter your bloodstream to begin squeezing their way through. Your intestinal lining becomes compromised causing serious implications for your immune system. 

II. Leaky Gut, Dysbiosis, and Immunity

Leaky gut and/or dysbiosis can send your immune system into a tailspin. Here’s how:

  1. As harmful substances leak into your bloodstream, bodily inflammation occurs. Your immune system can and/or will then go into overdrive in an attempt to address the perceived threats.
  2. Due to the damage to your intestinal lining, your gut cannot properly digest food. This will disrupt your microbiome’s homeostasis. Dysbiosis results.
  3. The dysbiosis then triggers your immune system causing your body to ramp up its immune response.
  4. The ramped up immune response kicks off a chain reaction of rampant inflammation and increased dysbiosis. The result? Even more damage to the lining of your gut!

This downward spiral of dysbiosis and inflammation burns out your immune system – leaving it with less and less energy to fight off foreign invaders. Fortunately, there are some simple steps you can take to heal your gut and ensure your immune system is firing on all cylinders. We’ll discuss that in part two of “How to Heal Your Gut for a Stronger Immune System.”



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Doctor of Clinical Nutrition | Certified Nutrition Specialist