Can probiotics boost your immune system? The answer, as you’ll learn below, is yes … but there are some caveats.
In this article we’ll review several research studies that have explored the role probiotics play in immunity and reveal what, if any, probiotic strains may help improve your immune health. We’ll also talk about the right foods to eat to boost your immunity and situations in which you should probably avoid probiotics.
Let’s dig in …
The Microbiome, Explained
You have an estimated 40 trillion bacterial cells living inside your body at any given time.
A good chunk of these microorganisms live in your gut and are part of your “microbiome,” the collective community of microbes that reside with you.
The microbiome plays quite the important role in your body, particularly when it comes to immunity …
Scientists have discovered that 70-80 percent of your immune system is controlled by your microbiome.
And your gut microbiome is largely shaped by what you eat and drink, as we’ll explore further below. First, let’s talk probiotics …
What Are Probiotics?
Probiotics are beneficial bacteria that help keep your body healthy and working well. These good bacteria can provide assistance in a number of interesting ways.
Benefits of Probiotics
Probiotics can help you maintain a healthy balance in your body by:
- Supporting your immune function and controlling inflammation.
- Helping your body digest food.
- Keeping bad bacteria from getting out of control and making you sick.
- Creating vitamins.
- Helping support the cells that line your gut to prevent bad bacteria that you may have consumed (through food or drinks) from entering your blood.
Probiotics are commonly used by medical professionals to treat the following conditions:
- Diarrhea
- Irritable bowel syndrome
- Ulcerative colitis
- Crohn’s disease
- H. pylori (the cause of ulcers)
- Vaginal infections
- Urinary tract infections
- Infection of the GI tract caused by Clostridium difficile
- Pouchitis (a possible side effect of surgery that removes the colon)
- Eczema in children
Let’s take a deeper dive into the role probiotics play in your immune health, specifically.
Probiotics and Immune Health: What We Know Based on Current Research Studies
Study #1: Beneficial Effects of Probiotic Consumption on the Immune System
According to this 2019 study published in the Annals of Nutrition and Metabolism medical journal:
Probiotic bacteria have significant effects on the functionality of the mucosal and systemic immune systems through the activation of multiple immune mechanisms.
The researchers in the study discovered that probiotic bacteria induce signals in the intestine that improve the behavior of the immune system and the host’s health. Probiotic bacteria were deemed to be an “effective tool for the maintenance of the intestinal homeostasis and the stimulation of the mucosal immune system.”
Study #2: Prospective Study of Probiotic Supplementation Results in Immune Stimulation and Improvement of Upper Respiratory Infection Rate
In a 2018 double-blind, randomized, controlled trial, researchers found that a 3-strain probiotic supplement was “safe and effective for fighting the common cold and influenza-like respiratory infections by boosting the immune system.”
Probiotics do appear to be somewhat effective in preventing the common cold. More research is needed but early results are promising.
“Probiotics are particularly helpful for maintaining normal bowel function and good digestive health,” says Bruce Eisendorf, M.D., a family medicine doctor at the Palo Alto Medical Foundation. “They also keep your immune system strong so you can fight and prevent infection.”
Study #3: Probiotics and Immune Health
A 2011 study found that:
Probiotics showed therapeutic potential for diseases, including several immune response-related diseases, such as allergy, eczema, viral infection, and potentiating vaccination responses.
Which Probiotics Are Best for Immunity?
Here are the strain-specific probiotics that may work for boosting your immune system:
| Probiotic Strain | Immune System Benefit |
| Bifidobacterium bifidum | Reduces cold and flu incidence. |
| Lactobacillus brevis | Reduces the incidence of flu. |
| Lactobacillus GG | Decreased risk of upper respiratory infections for children in daycare. |
| Lactobacillus acidophilus and Bifidobacterium bifidum | Reduces the risk of colds in school-aged children. |
| Lactobacillus rhamnosus | Reduces the incidence of pneumonia in people in the intensive care unit. |
| B. longum | Helps prevent the flu in elderly patients. |
| Lactobacillus plantarum and Lactobacillus paracasei | Reduces the number of days with symptoms and severity of colds. |
*Shameless Plug Alert: Our digestive health supplement, Pure Food DIGEST, contains ALL of these probiotic strains!
How to Build a Healthy Immune System By Feeding Your Microbiome the Right Foods
One way to improve the levels of healthy bacteria in your gut without probiotic supplements is to eat more foods these “good bacteria” like to eat—namely, fiber-rich foods.
This means increasing your intake of:
- Vegetables
- Fruits
- Beans/legumes
- Whole grains
- Nuts and seeds
Getting all your fiber from a single source (like a fiber supplement, for example) is not the best way to boost your gut health and immunity.
Your goal should be to eat a variety of fiber-rich foods each day.
Another way to promote a healthy gut and immune system is to eat foods that already contain beneficial bacteria (probiotics).
This includes:
- Yogurt, kefir, and other cultured dairy products (there are plant-based options available now too).
- Kim-chi, sauerkraut, and other fermented vegetables.
- Miso, tempeh, natto, and other fermented soy products.
- Kombucha (fermented tea).
All of these products are available on grocery store shelves or you can make them yourself, which is actually quite fun. My personal DIY foods: kombucha, preserved lemons, fermented pepper paste, and pickles.
Is it Safe to Take Probiotics When You’re Sick?
Probiotic supplements are generally safe for healthy people.
Studies show that taking probiotics may help you get sick less and reduce the amount of time you’re sick for (in regards to common colds/respiratory infections).
But there are some situations where beneficial bacteria (either from foods or supplements) can cause adverse affects.
Acute illnesses such as pancreatitis, Crohn’s, colitis, and celiac disease can lead to increased intestinal permeability, which is when bacteria penetrate the lining of the gut far enough to cause an inflammatory reaction from your immune cells. If your gut is already inflamed, that can spell trouble.
Those with compromised immune systems, either from a severe illness or due to medical treatment for a disease, are also generally advised to avoid probiotic foods and supplements. Some studies have found that using probiotics in severely ill or immunocompromised individuals can increase the risk of adverse effects such as infections.
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