Probiotics are live microorganisms in the gut that can support the immune system by optimizing the gut microbiome, strengthening the intestinal barrier function, stimulating immune cells, and warding off pathogens.
Your immune system performs the critical function of protecting your body against threats that can lead to infections and other health issues. Your gastrointestinal tract, or gut, is a vital part of your immune system.
The beneficial bacteria in your gut work with your immune system to protect your health and guard against harmful microorganisms.
Probiotics can support your immunity by helping to balance your microbiome for optimal gut health. In this article, we’ll take a look at how the gut, the immune system, and probiotics interact with one another.
Gut Health and The Immune System
The immune system includes the innate (general) and adaptive (specialized) immune systems.
Innate immunity consists of physical barriers like skin and mucous membranes that keep out foreign substances and special proteins and immune cells, also known as defense cells, that work quickly to attack invading germs.
Adaptive immunity comprises T-cells, B-cells, and specialized proteins called antibodies that can identify and destroy specific bacteria, viruses, and other foreign substances.
The gastrointestinal tract is an essential part of the immune system. It hosts approximately seventy to eighty percent of the immune cells in your body. One of its key functions is to protect the body from harmful microorganisms (pathogens). The gut’s mucosal barrier is one of its first defenses against pathogens.
The gut microbiome and the immune system continually communicate and influence each other’s development and function. The immune system regulates the colonization of the gut microbiome, and the microbiome stimulates the production and activation of both innate and adaptive immune cells.
The microbiome also protects digestive system health by inhibiting the ability of pathogens to colonize, overgrow, and damage the gut.
The beneficial gut bacteria in the microbiome continually monitor for and adjust their ability to inhibit pathogens. They also produce byproducts, such as short-chain fatty acids, with benefits for immunity. Short-chain fatty acids reinforce the intestinal barrier by enhancing its production of protective mucus and anti-microbial compounds.
Probiotics can optimize the gut microbiome for improved immune function. They block pathogens by competing with them for resources and by producing short-chain fatty acids that strengthen the gut barrier. Probiotics can ward off common pathogens like E. coli and H. pylori.
Multiple clinical studies have found that probiotic microbes improve diarrhea, including diarrhea caused by bacteria or viruses, decreasing its incidence, duration, and severity.
Lactobacillus strains, in particular, have been found to reduce infectious diarrhea. Other gut health benefits of probiotics include optimizing digestion and improving gut motility.
Can Probiotics Keep You From Getting Sick?
While taking probiotics certainly can’t guarantee that you’ll never get sick, they may boost your immune function and help your body ward off certain pathogens.
In addition to its role in gut immunity, the microbiome impacts immune health and resistance to germs throughout the body. The beneficial byproducts of gut flora, like short-chain fatty acids, circulate and affect diverse immune cells.
Disturbances in the gut flora can diminish immune responses both in the gastrointestinal tract and other parts of the body. Studies have linked alterations in the microbiome with conditions affecting multiple body systems; these imbalances may contribute to gastrointestinal, neurological, cardiovascular, and respiratory disorders.
Lower diversity of the microbiome in older adults has been associated with reduced immune function and greater susceptibility to infections. Immune function progressively declines in older adults. This lowered immunity can lead to weaker responses to pathogens and low-grade inflammation.
Lower diversity of the gut microbiome has also been linked with overactive immune responses, including the development of allergies and asthma. Some studies have found a reduced risk of allergic skin disorders in infants whose mothers took probiotics during pregnancy. Other studies providing probiotics to infants or children for allergy prevention have found mixed results.
Probiotics can impact immune health through the optimization of the gut microbiome and by interacting with immune cells.
One way that probiotics boost immunity is by increasing intestinal cells’ production of IgA antibodies. These antibodies are critical for mucosal membrane function and protect against pathogens in the gut and the respiratory, genital, and urinary tracts. IgA antibodies also have anti-inflammatory functions. The probiotic strains in Omni-Biotic Balance have been shown to increase secretory IgA, thus supporting immunity.
Some research has looked at changes in the immune cell function of people taking probiotics. One review of studies noted that ten of sixteen studies giving probiotics to healthy adults found improvement in their immune function, including increased T-cell and natural killer cell activity and reduced inflammation. Several of the studies with positive results included older adults.
Some studies have found that probiotic supplementation significantly increased flu vaccine antibodies in adults, including some studies with older adults. Other studies providing probiotics to older adults have not found significant effects on their vaccine response.
Research on probiotic supplementation for the prevention or treatment of infections has found mixed results.
Some studies have linked probiotic use with lower rates or reduced severity or duration of respiratory infections, particularly upper respiratory infections.
One review reported that three studies of probiotics found benefits for the common cold in healthy adults, including reduced incidence, duration, and symptoms. Results of the studies on probiotics and influenza infections were more inconsistent, with some finding enhanced immunity and others finding no impact on the incidence or severity of infection. One study found reduced rates of ear infections in infants given a combination of probiotics.
Some beneficial bacteria, particularly probiotic strains of the Lactobacillus species, are effective against bacteria and yeast that cause infection in the vaginal and urinary tracts. These good bacteria ward off pathogens by competing for adhesion sites, enhancing protective mucus, and stimulating immune cell production; they also contribute to the acidic pH of the vagina.
Some Lactobacillus strains have demonstrated activity against E.coli and other bacteria that can cause vaginal infections and may aid in their prevention and treatment. However, studies giving probiotics for the prevention of urinary tract infections, often caused by E.coli, have found inconsistent results.
Probiotics may not be safe for use in those with serious health conditions or immunosuppression.
What Kinds of Probiotics May Support Immune Function?
Probiotics can balance the gut microbiome and support immune function by strengthening the intestinal barrier and stimulating immune cells. Most probiotics ward off pathogens by competing for resources and blocking their attachment. Other specific effects on immunity vary by strain.
In a review of studies on probiotic supplementation and immunity in healthy adults, the studies that found positive effects on immune function mainly used single or multi-strains of Lactobacilli with some Bifidobacterium species. These included:
- Lactobacillus plantarum
- Lactobacillus paracasei
- Lactobacillus casei
- Bifidobacterium lactis
Other probiotics found to impact immunity positively include strains of Lactobacillus rhamnosus, Lactobacillus acidophilus, L. reuteri, B. animalis, B. breve, and S. thermophilus.
Many Lactobacillus species have anti-bacterial or anti-Candida effects. Lactobacillus strains such as L. casei and L. rhamnosus have been found to reduce acute infectious diarrhea.
Strains of L. plantarum, L. rhamnosus, L. acidophilus, and S. thermophilus were able to block the common bacteria E. coli in the gastrointestinal tract.
Bifidobacterium strains such as B. infantis have been found to reduce harmful bacteria in infants. Higher levels of Bifidobacterium species in the gastrointestinal tracts of breastfed infants have been associated with stronger immune function and protection against infection.
Omni-Biotic’s Immune Support Probiotic Omni-Biotic Balance is a multi-strain product providing several species of Lactobacilli and Bifidobacteria found to impact immune function positively.
A clinical study with sports students showed that taking Omni-Biotic Balance increased secretory IgA, which provides a first line of defense against pathogens in the gut. A separate study has shown that the probiotic strains in Omni-Biotic Balance increase the production of the anti-inflammatory cytokine interleukin-10 and reduce certain pro-inflammatory cytokines. Interleukin-10 induces the production of IgA antibodies. It also reduces inflammation in the body and protects against allergic and autoimmune processes.
Prebiotic supplements can also be a great way to keep your gut flora strong and diverse. Omni-Logic Immune is a precision prebiotic that was specifically designed with immune support in mind. The prebiotic fibers in Omni-Logic Immune support important Bifidobacteria and Lactobacilli. Added micronutrients such as Vitamin D and Zinc further support immune function.
Be sure to consult with your healthcare provider before taking probiotics if you have a compromised immune system or chronic health conditions.
How Long Do Probiotics Take to Support the Immune System?
If your goal is to optimize immunity, it’s important to choose a probiotic with research supporting its benefits for immune function.
It’s also crucial to find a product with sufficient numbers of probiotic bacteria able to survive the acidic conditions of the gastrointestinal tract. Supplements should contain 107 to 1011 CFU/g of viable bacteria, which should be labeled for the end of the product’s shelf life.
There is limited research on the timing of probiotics’ effects on the immune system. One lab study found that probiotics were incorporated into gut immune cells and enhanced their function within three days. However, the body is complex, and the timing of probiotics’ effects on the immune system will likely vary.
It may take up to several weeks for probiotics to affect the gut microbiome and impact immune function.
In a review of studies on probiotics’ ability to colonize the microbiome of healthy adults, most studies gave probiotics to participants for at least three weeks. The studies on immune function provided probiotics for at least four weeks, with some studies lasting much longer.
It’s important to note that probiotics’ ability to colonize the gut seems to be temporary and that effects can revert within one to three weeks after stopping supplements.
Supporting the gut microbiome with probiotics can help to optimize gut health and immune function. The right probiotic can offer benefits for immune health and protection against common pathogens.
Omni-Biotic’s multi-strain, multispecies probiotic Omni-Biotic Balance probiotic offers a range of beneficial Lactobacilli and Bifidobacteria for immune support. Omni-Biotic Balance contains six keystone strains that support a strong gut flora as the first line of defense against any bacteria and viruses entering the body via the gut. Furthermore, the probiotic strains in Balance support the body’s immune system and inflammatory response.