How can we support our immune health through the gut?

How can we support our immune health through the gut?

Cold and flu season is upon us once again. Did you know that our gut health plays a significant role in our immune system and could be the key combating germs this winter? Keep reading to learn more.

Caitlin Hall
by Emma Harrison
Student Dietitian
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The gut microbiome is a community of organisms that live in our gastrointestinal (GI) tract. It has evolved over time to develop symbiotic relationships with many aspects of our bodies, including our immune system. Our gut health may not be the first thing that comes to mind when we enter cold and flu season, but a well-balanced gut microbiome is essential for supporting our immune system and fighting off harmful pathogens. 

The immune system 

The immune system is the body’s defence system against foreign substances. It is comprised of cells, tissues, and organs; these components work together to fight against infections and adapt over time to prevent future infections. When we catch a cold or flu, the immune system is able to recognise the virus and fight it off – it will also remember this virus to fight it off more quickly and effectively in the future. A strong immune system can improve the body’s ability to fight the virus and reduce the duration of symptoms. 

The gut-immune axis 

Did you know that approximately 70% of the body’s immune system is located in the gut? Organisms such as bacteria, viruses, and fungi that live in our gut help to train the immune system to distinguish between pathogenic and harmless microorganisms.

So, how does it work? 

A single layer of cells forms the intestinal epithelium (otherwise known as the gut barrier). These cells communicate with our immune cells by sending chemical messengers called cytokines and chemokines – this helps our epithelium determine what organisms are harmful and should not be allowed to enter our bloodstream. 

The gut-associated lymphoid tissue (GALT) is found throughout the GI tract. This specialised immune tissue is the first line of immune defence in the digestive system; therefore, it is constantly surveying the environment for unwanted foreign substances. When it detects these substances (antigens), it signals to our immune B cells to produce antibodies. These antibodies aim to recognise and eliminate the antigens in a ‘lock and key’ style. This process helps our immune system learn what substances are harmless and which ones require our immune defence. 

Key components that help our immune cells are called short chain fatty acids (SCFAs). These are produced when prebiotic fibre is fermented by our gut microbiome. These SCFAs increase the activity of our immune cells and stimulate them to produce more of the antibody ‘keys’ to protect against pathogens. The SCFAs can also improve the function of the intestinal epithelium barrier by tightening any gaps and stimulating the production of a protective mucus barrier.  

The role of fibre 

When we consume prebiotic fibre, it is broken down by the gut microbiome and SCFAs are produced. If the gut microbiome is unbalanced, the production of SCFAs can decrease, and this can negatively impact the immune system (Kim, 2023). Without consuming enough dietary fibre (particularly prebiotic fibre), the drop in SCFA production can lead to a weakened intestinal barrier function, a reduced immune defence, and therefore an increased risk of infection. 

Eating for immunity this winter

The NHS recommends that we eat at least 30g of fibre a day, however the latest figures suggest that the average fibre intake for adults in the UK is only 18g. That’s 60% of what is recommended. With a reduced fibre intake, your good gut bacteria don’t have enough fuel to thrive and it opens us up to the possibility of reduced immunity as well as the increased likelihood of constipation and other GI issues. 

How to support your immune system through the gut

Consuming prebiotic-rich foods can increase the production of SCFAs in the gut and benefit the immune system. Some examples of foods that contain prebiotic fibre are: 

  • Garlic
  • Onion
  • Leeks 
  • Apple
  • Oats 
  • Barley 
  • Avocados 
  • Asparagus 
  • Flaxseeds 
  • Hazelnuts 
  • Almonds 
  • Walnuts 
  • Cashews 
  • Wheat bran
  • Mushrooms 

myota is your immune system’s best friend 

Although it is recommended to consume 30g of fibre a day, there are currently no official recommended daily intake levels of prebiotics. However, research suggests that we need around 3-5g of prebiotic fibre a day to see the benefits (Cereals & Grains Association, 2020). myota’s diverse prebiotic fibre blends provide 10g of fibre, providing 30% of your daily fibre needs, and 100% of your daily prebiotic needs. Our formulas are extensively tested to support gut, metabolic, immune, and brain health and help your body (and microbiome) thrive. 

References

  1. Cereals and Grains Association. “The Science of Prebiotics.” Cereal Foods World, vol. 65, no. 3, 2020, https://doi.org/10.1094/cfw-65-3-0027. 

  2. Kim, Chang H. “Complex Regulatory Effects of Gut Microbial Short-Chain Fatty Acids on Immune Tolerance and Autoimmunity.” Cellular & Molecular Immunology, vol. 20, no. 4, 1 Apr. 2023, pp. 341–350, www.nature.com/articles/s41423-023-00987-1, https://doi.org/10.1038/s41423-023-00987-1.

  3. Wiertsema, Selma P., 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, vol. 13, no. 3, 9 Mar. 2021, p. 886, https://doi.org/10.3390/nu13030886.