6 Interesting Facts About Your Immune System

Things You Should Know About Your Body’s Natural Defense System

Your immune system is an incredibly intricate network, composed of various specialized cells that collaborate to safeguard your health. Remarkably, it operates tirelessly, safeguarding your health around the clock, without requiring you to grasp its complexities.

However, your personal habits and life-style choices greatly influence your immune health. Knowing some key things about your immune system can help you support your overall health and well-being.

Here are several interesting facts worth knowing about your body’s innate defense mechanism:

70-80% of your immune system is housed within your gut.

While your immune system is a complex network of organs, cells and tissues located throughout your body – the vast majority of immune cells themselves hang out in your gut. More specifically, 70-80% of your body’s immune cells are located in the gut-associated lymphoid tissues (GALT) found in your gastrointestinal tract, including Peyer's patches in your small intestines.1

Scientists believe that the gut microbiome (comprised of trillions of microorganisms living in your gut) and immune system coevolved in a symbiotic relationships over time to protect human health. That means that your gut health and immune health are intricately related, and a healthy gut supports a healthy immune system.

You can activate your immune system for stronger defenses.

Certain immune health supplements and compounds possess the ability to activate your immune system at the cellular level. Typically, immune activators function by stimulating one specialized immune cell, such as NK cells, preparing the cell to fulfill its duties within your body's broader immune response.

IMMUSE™ postbiotic, on the other hand, has been scientifically shown to activate a unique type of immune cells knowns as plasmacytoid dendritic cells (pDCs), which act as leaders of the immune system.2 Once stimulated, pDCs send out signaling molecules that trigger the activation of an entire army of specialized immune cells, including natural killer (NK) cells, B cells and T cells, for a more comprehensive immune response.

Your immune system needs sleep to function properly.

Research indicates a bidirectional relationship between sleep and immunity: a robust immune system promotes better sleep, while adequate sleep is one of the most beneficial things for supporting healthy immune function.3

When you’re asleep, your body enters a highly active immune state, producing more immune cells and making new antibodies among other activities. All of which requires a lot of energy. Energy that isn’t available during waking hours.

Not getting enough sleep throws your entire immune system off balance, weakening your immunity. Clinical studies have shown that short sleep durations and poor sleep quality can increase susceptibility to the common cold.4

Spending time in nature helps boost your immunity.

Research shows that immersing yourself in natural settings can promote positive immunological parameters, such as anti-inflammatory effects and increased NK cell activity.5

Scientists in Japan, where forest bathing (or shinrin-yoku) is a widely practiced form of preventative medicine, have found that inhaling phytoncides can bolster the immune system. Phytoncides are airborne chemicals released by trees and plants that contain antibacterial and antifungal properties. Research from Japan indicates that breathing in phytoncides increases the number and activity of NK cells in the bloodstream – enhancing the body’s innate immune response for a number of days.6

Laughter may also strengthen your immune system.

Laughter is truly one of the best medicines. Research shows that laughter triggers the release of feel-good endorphins, reduces stress hormones such as cortisol, lowers blood pressure and promotes an overall sense of well-being. It even gives your immune system a boost7,8

Scientists at Linda University in a 2006 study found that laughing increases your body’s production of infection-fighting antibodies and T cells in the blood, bolstering your immune system’s adaptive immune response. Additionally, laughter supports healthy immune function by mitigating the negative effects of stress, which can suppress your immune system.

Excessively working out can weaken your body’s immune response.

While getting regular physical activity can help strengthen your immune system, prolonged periods of intense exercise have been shown to suppress immune function. According to David Nieman, PhD, director of the Human Performance Lab at Appalachian State University and a leading figure in exercise and immunology research, pushing the body too hard for an extended duration is correlated with inflammation, oxidative stress and temporary immune impairment.

In fact, immune suppression is a prevalent symptom associated with overtraining, a condition characterized by an excessive exercise regimen without sufficient recovery9

In addition to getting enough rest, athletes can help support their immune system during training periods by adding IMMUSE postbiotic to their sports nutrition regimen. IMMUSE has been clinically shown to support exercise performance by activating the immune system as well as immune resiliency during training.10,*

Interested in learning more about IMMUSETM postbiotic and how it can support year-round health when taken regularly?* Click the button below.

Discover the Science Behind IMMUSETM



1Wiertsema S, et. al., The Interplay between the Gut Microbiome and the Immune System in the Context of Infectious Diseases throughout Life and the Role of Nutrition in Optimizing Treatment Strategies. Nutrients. 2021 Mar 9; 13(3): 886.

2Sugimura T, et al., Immunomodulatory effect of Lactococcus lactis JCM5805 on human plasmacytoid dendritic cells. Clinical Immunology. 2013 Dec; 149(3): 509-18.

3Besedovsky L, et al. The Sleep-Immune Crosstalk in Health and Disease. Physiol Rev. 2019 Jul 1; 99(3): 1325-1380.

4Prather AA, et al. Behaviorally Assessed Sleep and Susceptibility to the Common Cold. Sleep. 2015; 38(9): 1353-1359.

5Andersen L., et. al. Nature Exposure and Its Effects on Immune System Functioning: A Systematic Review. Int J Environ Res Public Health. 2021 Feb; 18(4): 1416.

6Li Q., et. al. Effect of phytoncide from trees on human natural killer cell function. Int J Immunopathol Pharmacol. 2009 Oct-Dec; 22(4): 951-9.

7Bennett MP, Lengacher C. Humor and Laughter May Influence Health: III. Laughter and Health Outcomes. Evid Based Complement Alternat Med. 2008 Mar; 5(1): 37-40.

8Hajar R. Laughter in Medicine. Heart Views. 2023 Apr-Jun; 24(2): 124.

9Kreher JB, Schwartz JB. Overtraining syndrome: a practical guide. Sports Health. 2012 Mar; 4(2): 128-38.

10KomanoY,et.al.,Efficacyofheat-killedLactococcuslactisJCM5805onimmunityand fatigue during consecutive high intensity exercise in male athletes: a randomized, placebo-controlled, double-blinded trial. Journal of the International Society of Sports Nutrition. 2018; 15(1): 39.