I get a lot of questions about the best supplements for immune support. As a naturopathic doctor, I appreciate the benefits of vitamins, minerals, and herbal remedies such as elderberry and echinacea. However, there’s another layer of immune health that’s extremely important yet often overlooked—the gut.
Your gut, and specifically the gut microbiome—the immense collection of bacteria, fungi, and viruses that reside in your colon—has a profound influence on multiple aspects of your health, including your immune function.
One of the best ways to support all levels of your immune system, including your gut, is with probiotics, prebiotics, and colostrum.
The Gut-Immune System Connection
You would expect that supporting the gut microbiome helps to protect against digestive disorders such as constipation, diarrhea, irritable bowel syndrome, intestinal permeability (leaky gut), and colitis. But where does the immune system fit it?
A significant proportion of your immune system is located in your gut. From birth onwards, gut bacteria “educate” the immune system, helping it to learn which microbes are harmful and need an immune response, and which are totally benign.
Exposure to a variety of germs via vaginal birth, breastfeeding, pets, dirt, and life in general promotes a desirable diversity and balance of gut microorganisms. This results in a robust and discerning immune system that should protect us throughout our lives.
Unfortunately, modern life is less than kind to the gut microbiome. Antibiotics, poor diet, sleep deprivation, stress, and other factors cause alterations and imbalances in these delicate microorganisms. Disruptions in the gut microbiome are linked with chronic infections, autoimmune diseases, allergies, inflammatory conditions, and other disorders related to immune dysfunction. This underscores the importance of nurturing your gut microflora.
The good news is that there are three nutrients that can help to support your gut and immune system.
#1 Start with Probiotics
Probiotics are live beneficial microorganisms that help to keep your gut healthy—as well as crowd out the potentially harmful bacteria that we come into contact with every day. Whether you get them through probiotic-rich foods like yogurt, kefir, miso, and sauerkraut—or through probiotic supplements—these beneficial bacteria help to:
- Enhance the number and balance of beneficial bacteria that keep your gut healthy.
- Suppress the growth of harmful, disease-causing microbes.
- Support the intestinal lining, helping to keep connections between your cells tight and reducing “leaky gut,” which is associated with digestive problems and autoimmune diseases.
- Increase the activity of macrophages and T cells, which are the “first responders” of your immune system that protect you against infections.
- Activate regulatory T cells—called T-regs—which help prevent an excessive immune response and autoimmunity.
- Modulate or inhibit the production of inflammatory mediators such as cytokines and chemokines.
Lactobacillus, Bifidobacterium, Saccharomyces (probiotic yeast), and Bacillus (soil-based organisms) are the best-studied probiotics for gut health and immune support, and there are multiple strains in each of these broad categories. Clinical trials demonstrating the benefits of probiotics use specific strains, so it may not be fair to assume that all probiotic supplements and foods provide similar benefits.
As a general guideline, however, look for a probiotic that contains a variety of strains and at least 1 billion CFU (colony forming units = the number of live and active microorganisms). Take as directed.
#2 Support Probiotics with Prebiotics
Prebiotics are compounds that encourage the growth and activity of beneficial microorganisms—including those in your probiotic supplements. Found in many, though not all, fiber-rich plant foods, prebiotics pass through the stomach and small intestine unaffected by stomach acid and digestive enzymes and arrive in the colon more or less intact.
These non-digestible carbohydrates serve many critical functions:
- Providing fuel for the microflora inhabiting the gastrointestinal tract.
- Boosting the growth, diversity, and balance of beneficial microorganisms, which helps to keep potentially harmful microbes in check.
- Serving as a substrate, along with other fiber, for the production of short chain fatty acids (SCFAs), which provide energy for cells in the colon and stimulate T-regs that help with immune modulation.
- Enhancing the effectiveness of probiotic supplements and foods.
I usually suggest that patients get their prebiotics by eating lots of fiber. Chicory root, Jerusalem artichoke, and dandelion greens are particularly abundant in prebiotics. More common foods that are also good sources include garlic, onions, leeks, artichokes, asparagus, bananas, and apples.
If you have not been eating much fiber, build up gradually because it can cause bloating, gas, and discomfort. You can also get prebiotics in supplements, usually in the form of fructo-oligosaccharides (FOS) and inulin. Use per product instructions.
#3 Get Extra Protection From Colostrum
Colostrum is the first thing babies and other mammals consume after birth. Produced in the mammary glands for a few days until the mother’s breast milk comes in, colostrum helps prime the infant’s immune system.
Rich in immunoglobulins (IgG) antibodies, lactoferrin, proline-rich peptides, and other antimicrobial and immune-modulating compounds, colostrum strengthens the immune response, provides nutritional support, and supports the newborn’s intestinal tract.
You may be wondering what this has to do with you. Bovine colostrum from grass-fed cows, delivered in capsules or powders, also has therapeutic benefits for humans. Although it is not as well-studied as prebiotics and probiotics, it has been shown to:
- Increase protective IgA antibodies, which are secreted in the mucous membranes of the gut, lungs, sinuses, intestines, and saliva—and are critical to your immunity.
- Reduce diarrhea, both traveler’s and disease-related.
- Help correct intestinal permeability (leaky gut) and improve gut health issues.
I often recommend colostrum for gut healing, including leaky gut or persistent or chronic diarrhea to patients following a stomach flu. I also use colostrum for immune support, especially for people with low secretory IgA levels who seem to catch every cold and flu that comes along.
To purchase, look for bovine colostrum sourced from grass-fed cows. Both capsules and powders are acceptable, but make sure you take it on an empty stomach.
Your Gut & Overall Health Are Strongly Connected
Interest in the gut microbiome has skyrocketed in recent years—with good reason. In addition to its links with digestive and immune function, disruptions and imbalances in the gut microflora are also associated with depression, anxiety, weight gain, risk of diabetes and cardiovascular disease, and more.
Therefore, by cultivating healthy gut microflora—through the foods you eat and supplements you take—you’re not only supporting your gut and immune system but your overall health and well-being.