Medical science is currently spending more time and money on gut research than any other field of medicine. The EU has already funded 216 projects over €498million to promote metagenomics and to advance our knowledge of microbes [4]. Why? Because the medical fields are starting to understand the role the gut health play in all aspect of our health. "It is increasingly recognised that the microbiome can change our mind and health status, or switch on a wide range of diseases including cancer, cardio-metabolic diseases, allergies, and obesity” [4]. We are also starting to see more and more businesses, coaches and “gut specialists” promoting goods and services to “help fix your gut.”

Now is a fascinating time in microbiome research as scientists are attempting to figure out what species of bacteria are responsible for specific biochemical responses in the body. We are discovering relationships between many diseases and the gut microbiome. We are also finding connections between the gut microbiome and obesity.

The human gut is home to approximately 100,000,000,000,000 (100 trillion) microorganisms, collectively referred to as the “gut microbiota” [5]. Gut health and quality of life are inseparable. Most us of already know about the gut-brain connection [8], but are you aware of:

  • The gut immune system connection - The gut microbes regulate 70-80% of the immune system and influence blood sugar control [6,7].

  • The gut-skin connection [11]

  • The gut eye connection [12]

  • The gut muscle connection [13]

  • The gut bone connection [9]

  • The gut gonads connection

  • The gut ovary connection

  • The gut cardiovascular system connection [10]

  • The gut thyroid connection


There isn't a single organ system in the body that is not affected by the health of the gut. The human gut is lined with more than 100 million nerve cells—it's practically a brain unto itself. Gut health affects our sleep, mood, energy levels, cognitive function, memory, and more. The gut is designed to prevent unwanted materials from entering the bloodstream. The gut is the window that takes things from outside of the body and brings them into the bloodstream. The gut is also used to remove waste product from the body by drawing things in from the blood and passing them out of the body.

Two main variables impacting our gut health:

1. The Gut Barrier - Leaky Gut

The gut barrier, a multilayer system made up of intestinal epithelial cells and proteins, prevents the escape of non-nutritive (and potentially harmful) substances from the intestine into the bloodstream. When the structural integrity of the gut barrier is compromised, abundant proteins and other molecules escape from the gut into the blood; this phenomenon is referred to as leaky gut [16]. Leaky gut causes inflammation, which can cause fatigue, depression, anxiety, brain fog, insomnia, skin conditions, female and male hormone imbalance, memory loss, and hypothyroid symptoms. Inflammation in the gut has been shown to cause insomnia, and our readers know that sleep is the cornerstone of Sustainable Health.

I learned this firsthand as my insomnia was almost unbearable, and it didn't start to improve until I began to heal my gut. On occasions, my sleep is still not great, and I can link this to stress, which affects the gut. I’ve seen benefits from the potatoes diet, which is high in resistant starch.

It’s possible for someone to have a leaky gut and not experience any of the gut-related symptoms. Studies have shown leaky gut can manifest as eczema [17], autoimmune disease [18], obesity [19], and many other chronic health conditions. If leaky gut is left unmanaged, it can impact cognitive function, blood sugar management, and make it very difficult to improve other health-related issues.

Interesting fact: A group of people that commonly suffer from leaky gut are athletes. High performers can place additional stress on the gut by overtraining (especially high intensity) and under-recovering. The running community actualy have a name for it, they cal it “runners trot.”

2. The Gut Bacteria

The type of bacteria in the gut has been linked to immune system complications such as hypothyroidism, celiac disease, Irritable Bowel Syndrome (may affect as much as 30% of the population, up to 84% of IBS may be caused by an overgrowth of bacteria in the intestines), rheumatoid arthritis and joint pain, depression, food sensitivities, and IBD (inflammatory bowel disease). Merely taking a probiotic may not resolve these issues as there are many different spices of bacteria that need to be understood. Science is still trying to figure out the role each bacteria has to play, and there are only a few well researched probiotic supplements that can survive the harsh environment of the stomach. I often hear people talking about the probiotics in yogurt, which is a load of BS.

What should you know about gut bacteria?

  • Gut bacteria play an essential role in the breakdown of hormones and their removal from the blood. The removal of hormones is especially important for women because problems in this area can easily cause imbalances in estrogen. This can cause PMS, irritability, depression, weight gain, and accelerated aging. High levels of inflammation can cause higher testosterone in women and higher estrogen levels in men. This is why it’s not unusual for hormone-related symptoms to improve after improving gut health. This might look like improved libido, mood, PMS, energy, or stamina.

  • The skin is a reflection of the gut and certain skin conditions - pimples, lesions, rashes, and skin inflammation- have been clinically documented to improve after removal of inflammatory foods from the diet or to reduce unwanted bacterial overgrowth in the intestines.

  • Preliminary evidence showing that the treatment of a bacteria called H. pylori had been shown to reduce thyroid autoimmunity (Hashimoto’s disease).

  • Did you know that the occurrence of many health conditions associated with Western society is significantly lower in people who grew up on animal farms? Farm life gives us a higher exposure to a variety of bacteria, bacteria that Westerners are becoming increasingly deficient in.

  • When scientists want to do leaky gut tests on animals, they give the animals alcohol because it contributes to intestinal permeability (leaky gut).

Nutrient Absorption (malabsorption)

Although you might be eating a healthy diet and following your macros, if your not absorbing the nutrients its almost impossible to improve your energy, mood, sleep, lean muscle gain, fat loss and overall healthspan. This is known as malabsorption and symptoms can include:

  • Dry and thin hair

  • Dry and aged skin

  • Fatigue

  • Cravings

  • Vitamin and mineral deficiencies (measured by blood work)

  • Slow metabolism and weight gain

  • High blood sugar and high LDL cholesterol (bad stuff)

  • Gas, bloating, diarrhoea, loose stool, reflux, undigested food in stool, heartburn

Is there such a thing as “good for your gut foods"?

A large part of determining your sustainable diet involves figuring out which foods are inflammatory for your body and which ones are not. This is another reason why no one diet works for everyone. We need to create an optimal environment for each through an individualised approach. Foods, such as refined carbohydrates and industrial seed oils, are an established risk factor for gut dysbiosis [14].

As medical research start to explore gut bacteria, a new market is growing around foods and products that contain probiotics and prebiotics. However, this overlooks the fact that many people have an overgrowth of bacteria and consuming probiotic and prebiotic foods can encourage even more overgrowth. If you have ever felt bloated or gassy after consuming probiotic or prebiotic foods like kombucha, sauerkraut, kefir, etc.. you might have been feeling the effect of Small Intestine Bacteria Overgrowth (SIBO).

Prebiotic and fibre, which are often found in carbohydrate foods, can be used to feed the gut bacteria and improve gut health if someone already has a healthy gut. Prebiotic and fibre are eaten by the gut bacteria, which then produce short-chain fatty acids (SCFA's). SCFA’s nourish our gut, reduce inflammation, and can help to heal a leaky gut. However, overweight and obese people can often produce excessive levels of SCFA’s, which can contribute to weight gain [1,2]. Increased levels of certain bacteria have been found in those who are overweight [3]. Many people need to avoid these so-called “gut healthy foods” until they clean up their SIBO.

Should you be taking a probiotic?

There are many different types of probiotics, and merely adding enormous amounts of bacteria is not the solution to improving your health, more is not better. Think of the gut and the gut bacteria as a living breathing ecosystem like a rainforest. Just like the rainforest, the health of the ecosystem depends on the environment that supports it. Sunshine, rain, climate, insects, fungus, plants, animals, rivers, the soil, pollution, deforestation, etc.. all have a role to playing the health of the rainforest. By providing your gut ecosystem with the healthiest environment possible, you can heal the gut and increase your healthspan.

This can be a difficult question to answer as it depends on the current health of your gut and what types of bacteria are living there.

  • Do you have high histamine levels?

  • Are you overweight or obese?

  • How is your stool?

  • What is your diet like, do you eat more organic foods and no processed foods?

  • How stressed are you?

  • Do you overtrain?

  • Hows is your sleep?

  • How often have you taken antibiotics?

  • Where you vaginal born?

  • Have you been exposed to high levels of toxins or chemicals?

  • Do you have leaky gut symptoms?

  • Do you have SIBO symptoms?

There are so many factors that can contribute to the balance of bacteria in the gut and the only real way to know what is going on inside is to work with an investigative doctor or functional medicine practitioner to do gut tests.

Where should you start?

Life on the outside affects life on the inside. If you abuse your body with bad food, lack of sleep, stress, overtraining, smoking, alcohol, recreational drugs, exposure to toxins and chemicals, what do you think will happen on the inside?

Many of the issues associated with gut health are initially caused by inflammation and problems with the gut bacteria. Several environmental factors cause these problems, far too many to cover in this posts (stress, NSAIDS, antibiotics, birth control pills, C-section birth, lack of breastfeeding, poor quality sleep, etc…).

One of the significant causes is inflammatory foods. Foods that your body does not do well on because they cause an inflammatory response, which set your immune system alight and can lead to autoimmune diseases. Some of the main culprits that cause an inflammatory response include gluten, dairy, sugar, eggs and soy. Be aware that your inflammatory foods may not be the same as someone else as your gut is unique and unlike anyone else due to your environment and lifestyle. Some inflammatory foods do not cause any noticeable symptoms at first, and it can take years for the accumulation of inflammation to appear. It’s for this reason we recommend avoiding foods like gluten and soy 100% of the time.

Inflammation in the gut often leads to an inability to absorb critical minerals like iron and B vitamins, which can then lead to fatigue. Being low in iron or B vitamins can be the first sign that you have underlying gut problems.

A reset diet can be an excellent place to start as it is designed to reduce inflammation, improve digestion, burn fat, identify food intolerances, reduce allergic reactions or intolerance reactions, boost energy, regulate blood sugar, and stabilise mood. It almost sounds too good to be true, right?

Healing the gut and improving gut health is a tricky business because all of us are unique, and we can all have a different response to a particular set of foods. Some guts will thrive with more carbs and fibre, and others will do better on more fat and fewer carbohydrates. It would be best if you learned to listen to your gut, learn what makes it happy and what makes angry, and to take care of it like an ecosystem that is keeping you alive. Take note of your stress and anxiety levels as chronic stress alters the gut microbiota, and this may be one of the critical mechanisms by which stress contributes to so many chronic health issues [15]. Stress management tools like meditation and mindfulness have been shown to affect gut health.

If life on the inside is healthy and thriving, life on the outside can be the same.

If your feeling a little lost and uncertain about you gut health please feel free to reach our and contact us. Our health coaching service is designed to support and guide you through any health and performance problems you are dealing with.

Read more TSTM articles on GUT HEALTH

As always, this information is not designed to diagnose, treat, prevent or cure any condition and is for information purposes only – please discuss any information in this post with your health care professional before making any changes to your current lifestyle.


  1. Effects of gut microbes on nutrient absorption and energy regulation. Krajmalnik-Brown, et al, 2012

  2. Fecal butyrate levels vary widely among individuals but are usually increased by a diet high in resistant starch. McOrist AL, et al, 2011

  3. Macronutrient Intake in Obese Subjects with or without Small Intestine Bacterial Overgrowth: An Alimentary Survey

  4. Microbiome Research Is Becoming the Key to Better Understanding Health and Nutrition, Dirk Hadrich, 2018

  5. Host-Bacterial Mutualism in the Human Intestine, Fredrik Bäckhed, et al. 2005

  6. Allergy and the gastrointestinal system, G Vighi, et al. 2008

  7. Mechanisms Linking the Gut Microbiome and Glucose Metabolism, Kristina M. Utzschneider, et al. 2016

  8. The Brain-Gut-Microbiome Axis, Clair R. Martin, 2018

  9. The impact of the intestinal microbiome on bone health, Jian Zhang, et al. 2018

  10. Gut Microbiota in Cardiovascular Health and Disease, W.H. Wilson Tang, et al. 2018

  11. The Gut Microbiome as a Major Regulator of the Gut-Skin Axis, Iman Salem, et al. 2018

  12. Human Microbiota and Ophthalmic Disease, Louise J. Lu, et al, 2016

  13. Aging Gut Microbiota at the Cross-Road between Nutrition, Physical Frailty, and Sarcopenia: Is There a Gut–Muscle Axis?, Andrea Ticinesi, et al. 2017

  14. Old Fashioned vs. Ultra-Processed-Based Current Diets: Possible Implication in the Increased Susceptibility to Type 1 Diabetes and Celiac Disease in Childhood, Sandra V. Aguayo-Patrón, et al. 2017

  15. Chronic stress promotes colitis by disturbing the gut microbiota and triggering immune system response, Xinghua Gao, et al. 2018

  16. Gut permeability, obesity, and metabolic disorders: who is the chicken and who is the egg? Alessio Fasan. 2017

  17. Increased Intestinal Permeability in Atopic Eczema, Michael GPike, et al. 1986

  18. Leaky Gut As a Danger Signal for Autoimmune Diseases, Qinghui Mu, et al. 2017

  19. Potential mechanisms for the emerging link between obesity and increased intestinal permeability. Teixeira TF, et al. 2012