2nd July 2023

Why Is Gut Health Important?

There has been a recent growing recognition of the importance and involvement that our gut microbiome has in our overall health. Although it may seem as simple as ‘you are what you eat’, getting to grips with the nitty-gritty can be confusing.

In this article, we’ll start with the key terms you’ll need to know, discuss what the gut microbiome is, why it’s so essential and the health benefits of having good gut health. After learning the basics, read our top five ways to improve your gut health here

When discussing anything to do with gut health, there are some key terms to familiarise yourself with:

  • Microbes: the trillions of viruses, fungi and bacteria that live in your body, otherwise known as microorganisms. Many are essential for our health while some are responsible for diseases which make us sick.
  • Bacteria: single-cell organisms which live in or on our body. Less than an estimated 1% of bacteria are responsible for diseases, and most are essential to help us digest food and fight germs.[1]
  • Microbiome: the collective group of microbes and microorganisms in a particular environment, like your gut, for example.
  • Microbiota diversity: a measure of how many different species of microbes there are, and how evenly they are distributed in the environment.[2] The more microbiota diversity in a microbiome, the better!
  • Short-chain fatty acids (SCFAs): SCFAs are fatty acids with fewer than 6 carbon atoms, that are produced when friendly bacteria ferment fibre in your colon.[3] They are the main source of nutrition for the cells in your colon.

What is the gut microbiome?

We’ve established that the gut microbiome is a collective group of microbes which live in your gastrointestinal tract (GIT), but did you know that it’s essential for keeping your heart, brain, immune and digestive systems healthy?

The human genome consists of about 23,000 genes, whereas the microbiome consists of over three million genes.[4] Additionally, there are up to one thousand different species of bacteria in the GIT, which can be found mostly in your large intestine, and the microbes in your gut weigh up to 1-2kg together. Your gut microbiome diversifies as you grow.[5] 

That’s a lot of organisms all working very hard to keep your systems balanced and healthy!

Why is gut health important?

Gut health affects more aspects of your overall health than you may realise, and can help to protect against chronic illnesses. In fact, collectively, your intestinal tract is the largest contributor to your immune system, with about 80% of your immune-producing cells living there.

Gut microbiota are essential for the fermentation of non-digestible substrates like dietary fibres. This process supports the growth of specialist microbes which produce short-chain fatty acids (SCFAs). As the main source of nutrition for the cells in your colon, SCFAs play an important role in health and disease, and support the metabolism of carbohydrates and fat. They have been linked with reducing the risk of inflammatory diseases, type 2 diabetes, obesity, and heart disease. Eating certain types of fibre supports the production of short-chain fatty acids, for example, artichokes, garlic, leeks and onions. 

To put it simply, think of the microbiome as the rainforest of the body: it’s essential to keep our bodies healthy, just as rainforests are vital for our earth.

Benefits of a healthy microbiome

Keeping on top of your gut health has day-to-day benefits such as improving your mood, sleep and general digestion. It has also been shown to regulate anxiety, mood and pain and has even been shown to control brain health and the central nervous system.  

Additionally, a healthy gut has not only been shown to improve your overall immune system, but it also plays a part in protecting against specific chronic illnesses. It reduces the risk of all kinds of bowel diseases and intestinal disorders, such as irritable bowel syndrome (IBS), coeliac disease, and inflammatory bowel diseases like Crohn’s disease and Ulcerative colitis. Short-chain fatty acids appear to make the biggest difference in not only reducing the risk of these diseases, but also in improving symptoms in those who already have them. 

A healthy gut microbiome aids in the prevention and management of many more health issues, aside from just intestinal disorders. Extra-intestinal disorders such as metabolic syndrome, cardiovascular disease, asthma, allergies and obesity have also been linked to good gut health.

What causes poor gut health?

Although there is a heritable component to gut microbiota, environmental factors have a much larger effect on the microbiome. 

A poor diet of ultra-processed foods, alcohol, antibiotics and smoking are some of the external factors that affect microbiota. Stress and lack of sleep are lifestyle environmental factors that affect the gut, so it’s important to make sleep a priority when trying to live a healthy lifestyle, alongside diet and exercise.

Just one thing you can do to start improving yours!

Studies show that the typical ‘Western diet’ can get in the way of a healthy gut microbiome and has strong associations with a wide range of diseases, including obesity, metabolic syndrome, type 2 diabetes and cardiovascular disease. The Mediterranean diet which supports a healthy gut is considered the healthiest option, associated with the prevention of many of these diseases. 

If you try just one thing to help your gut health, give eating a Mediterranean-style diet a go. To find out more about this science-backed lifestyle change, sign up to The Fast 800 Online Programme where we have different meal plans based on your goals and a community of members and experts who can help guide you on the journey. This invaluable resource also houses exercises for different abilities, and mindfulness tools to aid with sleep and stress. 

The Programme has hundreds of recipes packed with fibre, probiotics and prebiotics, and essential nutrients needed for good gut health and to reduce the risk of chronic illness. 

Try signing up to our Online Programme today, and your gut will certainly thank you for it.


 InformedHealth.org [Internet]. Cologne, Germany: Institute for Quality and Efficiency in Health Care (IQWiG); 2006-. What are microbes? 2010 Oct 6 [Updated 2019 Aug 29].Available from: https://www.ncbi.nlm.nih.gov/books/NBK279387/

Valdes A M, Walter J, Segal E, Spector T D. Role of the gut microbiota in nutrition and health BMJ  2018;  361 :k2179 doi:10.1136/bmj.k2179

Silva YP, Bernardi A, Frozza RL. The Role of Short-Chain Fatty Acids From Gut Microbiota in Gut-Brain Communication. Front Endocrinol (Lausanne). 2020 Jan 31;11:25. doi: 10.3389/fendo.2020.00025. PMID: 32082260; PMCID: PMC7005631.

Valdes A M, Walter J, Segal E, Spector T D. Role of the gut microbiota in nutrition and health BMJ  2018;  361 :k2179 doi:10.1136/bmj.k2179

Bäckhed F, Roswall J, et al. Dynamics and Stabilization of the Human Gut Microbiome during the First Year of Life. Cell Host Microbe. 2015 May 13;17(5):690-703. doi: 10.1016/j.chom.2015.04.004. Erratum in: Cell Host Microbe. 2015 Jun 10;17(6):852. Jun, Wang [corrected to Wang, Jun]. Erratum in: Cell Host Microbe. 2015 Jun 10;17(6):852. PMID: 25974306.

Ríos-Covián D, Ruas-Madiedo P, Margolles A, Gueimonde M, de Los Reyes-Gavilán CG, Salazar N. Intestinal Short Chain Fatty Acids and their Link with Diet and Human Health. Front Microbiol. 2016 Feb 17;7:185. doi: 10.3389/fmicb.2016.00185. PMID: 26925050; PMCID: PMC4756104.

Cryan JF, Dinan TG. Mind-altering microorganisms: the impact of the gut microbiota on brain and behaviour. Nat Rev Neurosci. 2012 Oct;13(10):701-12. doi: 10.1038/nrn3346. Epub 2012 Sep 12. PMID: 22968153.

Cryan JF, Dinan TG. Mind-altering microorganisms: the impact of the gut microbiota on brain and behaviour. Nat Rev Neurosci. 2012 Oct;13(10):701-12. doi: 10.1038/nrn3346. Epub 2012 Sep 12. PMID: 22968153.

Rooks MG, Garrett WS. Gut microbiota, metabolites and host immunity. Nat Rev Immunol. 2016 May 27;16(6):341-52. doi: 10.1038/nri.2016.42. PMID: 27231050; PMCID: PMC5541232.

Russo E, Giudici F, Fiorindi C, Ficari F, Scaringi S, Amedei A. Immunomodulating Activity and Therapeutic Effects of Short Chain Fatty Acids and Tryptophan Post-biotics in Inflammatory Bowel Disease. Front Immunol. 2019 Nov 22;10:2754. doi: 10.3389/fimmu.2019.02754. PMID: 31824517; PMCID: PMC6883404.

Carding S, Verbeke K, Vipond DT, Corfe BM, Owen LJ. Dysbiosis of the gut microbiota in disease. Microb Ecol Health Dis. 2015 Feb 2;26:26191. doi: 10.3402/mehd.v26.26191. PMID: 25651997; PMCID: PMC4315779.

Rothschild, D., Weissbrod, O., Barkan, E. et al. Environment dominates over host genetics in shaping human gut microbiota. Nature 555, 210–215 (2018). https://doi.org/10.1038/nature25973

Ahn J, Hayes RB. Environmental Influences on the Human Microbiome and Implications for Noncommunicable Disease. Annu Rev Public Health. 2021 Apr 1;42:277-292. doi: 10.1146/annurev-publhealth-012420-105020. PMID: 33798404; PMCID: PMC8641399.

Nagpal R, Shively CA, Register TC, Craft S, Yadav H. Gut microbiome-Mediterranean diet interactions in improving host health. F1000Res. 2019 May 21;8:699. doi: 10.12688/f1000research.18992.1. PMID: 32704349; PMCID: PMC7359750

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