Probiotics have gained a lot of attention in recent years for their potential health benefits, including improving digestion, promoting mental health, and boosting the immune system. In this blog post, we’ll focus on the latter – how probiotics can bolster the body’s natural defenses against pathogens and disease.
What Are Probiotics?
Before we dive into the science supporting probiotics’ immune-boosting abilities, let’s start with a quick refresher on what exactly they are.
Probiotics are live microorganisms, mostly bacteria and some yeasts, that when consumed in adequate amounts can confer health benefits to the host. The most common strains used in probiotic supplements and foods are Lactobacillus and Bifidobacterium.
While some may think of “bad” bacteria being eliminated from the body by antibiotics, probiotics are commonly known as “good” bacteria that can help regulate our digestive systems and support a healthy gut microbiome.
How Do Probiotics Affect the Immune System?
As we mentioned earlier, probiotics are primarily known for their gut health benefits. But the connection between our digestive system and immune system is strong, and there is growing evidence suggesting that probiotics can also boost our body’s defenses against infection and disease.
Here are three ways in which probiotics are thought to support the immune system:
1. Protecting Against Harmful Bacteria
The first line of defense against harmful bacteria is the gut’s barrier function. This barrier prevents harmful bacteria from entering the bloodstream and causing infections. Probiotics can help strengthen this barrier by blocking harmful bacteria from adhering to the gut lining, which reduces inflammation and promotes the growth of beneficial bacteria.
A 2010 study published in the Journal of Clinical Gastroenterology found that probiotics reduced the occurrence of upper respiratory tract infections in long-distance runners after they were exposed to a cold virus. This suggests that probiotics may play a role in reducing the risk of respiratory infections by supporting the body’s immune defenses.
2. Modulating the Immune Response
A healthy immune system needs to strike the right balance between attacking harmful pathogens and avoiding overreactions that lead to allergies and autoimmune diseases. Probiotics may help modulate this response by promoting the production of anti-inflammatory cytokines, which reduce inflammation and promote tissue repair.
A 2013 study published in the British Journal of Nutrition found that probiotics reduced inflammation and markers of oxidative stress in healthy young adults who were given a high-fat, high-carbohydrate meal. This suggests that probiotics may help mitigate some of the damaging effects of a poor diet on the immune system.
3. Supporting the Gut-Brain Axis
The gut and brain are connected through the gut-brain axis, which communicates bidirectionally through various signals. Probiotics are thought to influence this axis by regulating neurotransmitters like serotonin and gamma-aminobutyric acid (GABA), which have been linked to mood and behavior.
A 2016 study published in the Journal of Neurogastroenterology and Motility found that probiotics improved anxiety symptoms in patients with inflammatory bowel disease, likely through their effects on the gut-brain axis. This suggests that probiotics may have potential as a natural intervention for psychological distress.
Which Strains of Probiotics Are Best for Immune Support?
Not all probiotics are created equal, and different strains have different effects on the body. So which strains are best for immune support?
Lactobacillus rhamnosus GG and Bifidobacterium bifidum have the most evidence supporting their immune-boosting effects. A 2015 study published in the Journal of Clinical Gastroenterology found that Lactobacillus rhamnosus GG reduced cold and flu-like symptoms in children attending daycare centers.
Bifidobacterium bifidum has been found to increase the production of natural killer cells, which are a type of white blood cell that play a crucial role in the immune response against viruses and cancer cells.
Conclusion:
Probiotics show great promise as a natural way to fortify the immune system against disease and infection. While more research is needed to fully understand their mechanisms and effectiveness, the existing evidence strongly suggests that probiotics have a role to play in supporting immune health and overall wellbeing.
