"Probiotics – the trillions of beneficial bacteria that live in your digestive system – primarily support digestion and nutrient absorption, but they also play a significant role in supporting our immune system. "
This immune function includes various roles, such as an immunoregulatory function that keeps harmful bacteria in check to prevent them from colonising the gut and causing potential infections.
In addition, probiotics can help destroy pathogens like viruses that enter the digestive system, and interact with the immune cells (lymphocytes, epithelial cells, monocytes, and macrophages) that also live in the gut, influencing their production and activity to promote a balanced and effective immune response.
Specifically, probiotics play a role in cytokine and white blood cell production, including interleukins, which are important cell-signalling molecules in the immune system.
Some probiotic strains even strengthen the intestinal lining by repairing damage and tightening junctions between cells, which creates a more robust physical barrier to stop pathogens from entering the gut.
Furthermore, research shows that probiotics have anti-inflammatory effects, which could potentially help control the immune response throughout the body as chronic inflammation can weaken the immune system's ability to fight off infections.
Selecting strains
Estimates suggest there are over 50 genera and over 500 different species of probiotic bacteria, with variations in each leading to different subspecies. As such, it is important to understand which probiotic bacteria offer the most immune benefits.
Across numerous studies, two specific strains stand out for their impact on the immune system – Bifidobacterium and Lactobacillus. The human gut hosts about 30 species of Bifidobacteria and 52 species of Lactobacillus.
Most commercially-available probiotics include live strains of Lactobacillus acidophilus and Bifidobacterium bifidum.
Research-backed applications
A vast body of research demonstrates that Bifidobacterium and Lactobacillus strains help prevent intestinal permeability caused by inflammatory responses, support immune cell production and help fortify physical barriers.
In this regard, species like Lactobacillus rhamnosus (LGG®) have been linked to increased production of immunoglobulin A (IgA) antibodies, which play a vital role in protecting mucous membranes in the gut and respiratory tract from pathogens.
This strain has also been studied for its potential to reduce the frequency and duration of respiratory infections in children and adults, including COVID-19.
A 2021 study suggests that both Bifidobacterium and Lactobacillus strains offer potential in reducing inflammatory responses.
Furthermore, Lactobacillus acidophilus NCFM and Bifidobacterium animalis (subspecies lactis Bi-07) reduced the incidence of coughing (41.4%), a runny nose (28.2%), and fever (53%) in one study on 326 children during the winter season.
A 2017 study also highlighted how four Lactobacillus strains (L. rhamnosus GG, L. rhamnosus KLSD, L. helveticus IMAU70129, and L. casei IMAU60214) affected innate immunity by modulating the production of cytokines.
And Bifidobacteria and Lactobacillus were shown to suppress allergen sensitisation and were effective against allergic rhinitis.
Support your immune system
Backed by an ever-growing body of research, probiotics certainly have a role to play as a valuable tool to support a healthy gut microbiome and a well-functioning immune system this winter.
However, it is important to consider your individual needs when selecting the right product, which is best achieved in consultation with a qualified healthcare provider.
In general, ideal probiotic products to support your immunity this winter should contain a combination of probiotic strains, particularly Bifidobacterium and Lactobacillus strains.
It is also important to consider the amount of colony-forming units (CFUs) in a probiotic supplement, as this can impact its effectiveness. Most products offers a CFU count in the billions, with higher doses generally more potent and effective as more bacteria make it into your intestines after passing through the stomach and its acids.
A product that offers a CFU count of 5-10 billion is ideal for chronic use. You can also use products with higher CFU counts – as high as 30-50 billion – for acute 'loading' to treat specific conditions or following antibiotic use.
For the best results, it is vital to use probiotic supplements as part of a healthy lifestyle that includes a balanced diet rich in fruits, vegetables, and whole grains to provide prebiotic material to support probiotic colonies, along with regular exercise and sufficient quality sleep to support a strong immune system.
Products in focus:
Biogen Supreme Probiotic 4-Strain
contains Lactobacillus acidophilus, Lactobacillus rhamnosus, Bifidobacterium bifidum, and Bifidobacterium lactus.
Lifestyle Health Probiotic 9-Strain
contains Bifidobacterium bifidum, Bifidobacterium lactis, Bifidobacterium longum, Lactobacillus acidophilus, Lactobacillus casei, Lactococcus lactis, Lactobacillus plantarum, Lactobacillus rhamnosus, Streptococcus thermophilus
Biogen Supreme Probiotic 9-Strain
contains Lactobacillus acidophilus, Lactobacillus rhamnosus, Lactobacillus casei, Lactobacillus plantarum, Bifidobacterium bifidum, Bifidobacterium lactus, Bifidobacterium longum, Lactococcus actis, and Streptococcus thermophilis.
Food Grown Probiotic 10 Strain
contains Lactobacillus acidophilus, Lactobacillus rhamnosus, Bifidobacterium lactis, Lactobacillus paracasei LPC-37™, Lactobacillus casei, Lactobacillus reuteri, Lactobacillus gasseri, Lactobacillus salivarius, Bifidobacterium bifidum, and Bifidobacterium longum.
References:
- Mazziotta C, Tognon M, Martini F, Torreggiani E, Rotondo JC. Probiotics Mechanism of Action on Immune Cells and Beneficial Effects on Human Health. Cells. 2023 Jan 2;12(1):184. doi: 10.3390/cells12010184. PMID: 36611977; PMCID: PMC9818925.
- Xie Z, Zhang G, Liu R, Wang Y, Tsapieva AN, Zhang L, Han J. Heat-Killed Lacticaseibacillus paracasei Repairs Lipopolysaccharide-Induced Intestinal Epithelial Barrier Damage via MLCK/MLC Pathway Activation. Nutrients. 2023 Apr 4;15(7):1758. doi: 10.3390/nu15071758. PMID: 37049598; PMCID: PMC10097264.\
- Cristofori F, Dargenio VN, Dargenio C, Miniello VL, Barone M, Francavilla R. Anti-Inflammatory and Immunomodulatory Effects of Probiotics in Gut Inflammation: A Door to the Body. Front Immunol. 2021 Feb 26;12:578386. doi: 10.3389/fimmu.2021.578386. PMID: 33717063; PMCID: PMC7953067.
- Rao RK, Samak G. Protection and Restitution of Gut Barrier by Probiotics: Nutritional and Clinical Implications. Curr Nutr Food Sci. 2013 May 1;9(2):99-107. doi:10.2174/1573401311309020004. PMID: 24353483; PMCID: PMC3864899.
- Mikulic J, Longet S, Favre L, Benyacoub J, Corthesy B. Secretory IgA in complex with Lactobacillus rhamnosus potentiates mucosal dendritic cell-mediated Treg cell differentiation via TLR regulatory proteins, RALDH2 and secretion of IL-10 and TGF-β. Cell Mol Immunol. 2017 Jun;14(6):546-556. doi: 10.1038/cmi.2015.110. Epub 2016 Mar 14. PMID: 26972771; PMCID: PMC5518813.
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- Raheem A, Liang L, Zhang G, Cui S. Modulatory Effects of Probiotics During Pathogenic Infections With Emphasis on Immune Regulation. Front Immunol. 2021 Apr 8;12:616713. doi: 10.3389/fimmu.2021.616713. PMID: 33897683; PMCID: PMC8060567.
- Rocha-Ramírez LM, Pérez-Solano RA, Castañón-Alonso SL, Moreno Guerrero SS, Ramírez Pacheco A, García Garibay M, Eslava C. Probiotic Lactobacillus Strains Stimulate the Inflammatory Response and Activate Human Macrophages. J Immunol Res. 2017;2017:4607491. doi: 10.1155/2017/4607491. Epub 2017 Jul 5. PMID: 28758133;
