Is There a Link Between Your Gut Health and Your Immunity? - Probiotics
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Is There a Link Between Your Gut Health and Your Immunity?

Your body is overflowing with bacteria. In fact, it contains about 10 times as many bacterial cells as human cells. They live on your skin, in your respiratory tract, and throughout your digestive system. You acquire these bacteria during birth and all throughout the first few years of life—and they happily coexist with you in communities known as microbiomes. The largest microbiome in your body is found in your gut and it is home to as many as 1,000 different bacteria species. While some of these bacteria can cause infection, most are harmless and actually help maintain good health. Your bacterial makeup—known as your microbiota—fosters healthy growth and  protects you from harmful invaders. More specifically, the microbiota in your gut helps you to digest food, fortifies your immune system, and strengthens your intestinal barrier, which prevents pathogens and other harmful substances from leaking into the bloodstream. So in short, yes there is definitely a link between your gut health and your immunity.

Even though most of the time this bacteria is harmless and even helpful, in certain conditions some of the bacteria that live on the skin can become a problem. For example, bacteria that live on the skin can become a problem if you get a cut. Then the bacteria living on the surface of your skin may be able to enter into your body through the cut, getting in where they shouldn’t be and potentially causing an infection.

How Your Gut Influences Your Immunity

Let’s take a deeper dive into how your gut affects your immune system. Like every surface of your body, the lining of your gastrointestinal tract is covered in bacteria. This microecosystem (aka your microbiome) plays a large role in your health—and especially in promoting a healthy immune system. This makes sense since about 70 percent of your immune system lives in your gut. The relationship between your immune system and your gut is symbiotic. They’ve evolved together to eliminate harmful pathogens and make sure your body is protected. The gut microbiome acts as a gatekeeper and teaches key immune cells (like your T cells) to tell the difference between pathogens and your own tissue. When harmful pathogens do manage to mount an attack, these T cells mediate the situation and destroy the infected cells. This process is known as cell-mediated immunity.

Maintaining a healthy microbiome, and in turn a healthy immune system, can be as easy as making  few tweaks to your daily habits. First, because the overuse of chemically based household cleaners and hand sanitizers can disrupt the balance of your microbiota, it’s important to choose disinfectants with less harmful ingredients. It’s also important to support your beneficial bacteria with prebiotics. Prebiotics are simply undigestible fibers that act like food for your beneficial bacteria, helping them grow. You can also help maintain a healthy microbiome with a daily dose of probiotics.

Can Hand Sanitizer Upset Your Microbiome?

The global hand sanitizer market is expected to grow more than 600% due to the pandemic, according to research by market research firm Arizton.1 That’s not surprising since most of us probably bought more hand sanitizer over this past year than ever before. Just a squirt of the stuff and we felt a bit more protected from viruses, bacteria, or other potential invaders. But can the overuse of hand sanitizer and disinfectants pose a problem to our health and immunity?

There are some rumors claiming that hand sanitizer can disrupt your microbiome, and hence, your immune system. Fact or fiction? Currently, there is no scientific evidence to suggest that using an alcohol-based hand sanitizer is bad for your immunity or leaves you more susceptible to a bacterial or viral infection.

The only way that hand sanitizers have been found to leave you susceptible to pathogens is through its drying effect. The overuse of hand sanitizer can compromise your skin, resulting in dry and cracked hands. That can make it easier for unwanted bacteria to enter your skin and make its way into your bloodstream.3 If you do notice that your hands are getting dry and cracked, spend a little more time and attention on moisturizing.

When it comes to purchasing hand sanitizer, the CDC has a few tips. Their first suggestion is to choose a hand sanitizer that contains at least 60 percent alcohol when soap and water isn’t readily available.2 They also advise avoiding alcohol-based hand sanitizers that aren’t approved by the FDA. For best results, apply the alcohol-based sanitizer by rubbing it over all the surfaces of your hands until they are thoroughly dry.

Beyond Hand Sanitizer: Hand Washing for a Healthier Microbiome and Stronger Immunity

While hand sanitizers can be effective in a pinch, handwashing is the gold standard for preventing the spread of infection. Germs can easily travel from contaminated surfaces to your hands. When you then touch your eyes, nose, or mouth, these harmful pathogens can enter the body and find their way to your bloodstream. These pathogens not only affect areas like your respiratory tract, they can also disrupt your microbiome. Frequent handwashing can help prevent this transmission, which keeps both you and  the people you love healthy.

Properly washing your hands isn’t rocket science, but there are five key steps you should follow, according to the CDC.

  1. Wet your hands with clean, running water (hot or cold), turn off the tap and apply soap.
  2. Lather the back of your hands, between your fingers, and under your nails.
  3. Scrub your hands for at least 20 seconds.
  4. Rinse your hands well under the running water.
  5. Dry your hands using a clean towel or air dry them.


  1. Hand sanitizer market size by functional ingredients, product type, end-users, and distribution channels. Arizton Advisory & Intelligence. 2021; 435.
  2. How to select and use hand sanitizer. Centers for Disease Control and Prevention. 2020.
  3. Cogen AL, Nizet V., & Gallo RL. Skin microbiota: a source of disease or defence? British Journal of Dermatology. 2008;158(3):442-455.

This article is for informational purposes only. This article is not, nor is it intended to be, a substitute for professional medical advice, diagnosis, or treatment and should never be relied upon for specific medical advice.