The gut has become one of the most talked about topics in the past few years, with tens of thousands of books on it. However, there is one connection I believe has been ignored since its uprising – the gut-skin axis.

This connection is based on the deeply intertwined relationship between our gut and skin health. Simply put, when there is an issue with our gut, whether it be chronic inflammation, a leak, or a deficiency, its consequences are shown upon the skin.

For instance, I assume we have all been equally bombarded with how significant the health of our microbiome is, but we have hardly been told how to test its wellbeing. Many like to reference the quality and consistency of stools, but they often ignore the previously mentioned axis with our skin. For anyone not yet up-to-date, essentially, the gut microbiome refers to a diverse microbial population (bacteria) that lives within the gastrointestinal tract (gut). These microbes help with digestion, nutrient absorption, immune regulation, and hormone construction. About 70% of the immune system is located within the gut. Due to the large population of microbes, harmful pathogens that enter our system struggle to enter our bloodstream. But, when the barrier is compromised, toxins, bacteria, and undigested food enzymes can escape the lining and enter our bloodstream, triggering a vast swath of immune responses.

If our microbial population is skewed, then our immune system (gut bacteria) will consistently struggle to fight off any unwanted foreign invaders, triggering what we call inflammation. Labelled as dysbiosis, this imbalance has a snowball effect that could pertain to all aspects of our health, especially our skin.

So, firstly, when I say ‘skin’, I refer to not just the face (thinking of acne) but all skin across the body where any signs of inflammation could be occurring. For instance, this could refer to acne, eczema, psoriasis, rosacea, and urticaria, as examples. As with many conditions, these are inflammatory markers, often expressing underlying internal issues. As for these in particular, they are connected to the gut, which is why we have a relationship termed the gut-skin axis.

But this doesn’t really tell us much yet. Does our microbiome cause skin conditions? Does this mean that we can fix eczema with diet alone? Is acne just a sign of homogeneous microbiota? Essentially, in most cases, the answer is yes. Our microbiome is the primary driver in skin conditions. We can fix a vast array of skin issues with diet. A non-diverse microbiome can cause inflammatory responses.

The main culprits in dysbiosis are highly processed foods, low fibre-high carb diets, antibiotic usage, and stress. To cause a lack of bacteria diversity, one would have to kill all bacteria (antibiotics), allow carbohydrates to ferment in the gut by not eating any bulking agent, live in an overly sterile environment, constantly be stressed, excessively use probiotic supplements, and frequently fast. This all causes a homogeneous microbiome by starving the body of nutrition, overgrowing specific bacterial strains, and minimising exposure to natural environments.

After this occurs, our bidirectional communication network – the gut-skin axis – becomes severely impaired and forces the production of anti-inflammatory molecules to help maintain immune tolerance. When our biome becomes too homogeneous, it causes an overactive immune response because you may be short of certain bacteria with different jobs. For example, one of the most common lacking bacteria in someone with dysbiosis is butyrate. This bacterium’s job is to help break down fibre to stop carbohydrates from fermenting in the gut and leading to the influx of pathogens. If we lack this bacterium, it could lead to carbohydrates essentially decomposing within us. As a result, our gut lining would become weak, allowing pathogens to pass into the bloodstream, infecting our cells.

This is where our skin comes in. As a result of lacking anti-inflammatory effects from a homogeneous microbiome, the skin barrier also becomes weakened, as this is governed by the immune system. A compromised skin barrier allows irritants, pathogens, and allergens to penetrate more easily. Signs of this are shown through acne, eczema, psoriasis, rosacea, and urticaria, meaning when your gut is compromised, evidence is shown on the skin.

For this reason, it is always important to see why you may be having more acne than usual, or why your eczema may have flared up. One possibility could be diet related. But by no means does this mean all skin conditions, especially chronic ones, are fixable through diet. However, someone with conditions as mentioned above should be 100% on top of their diet, making sure they almost completely cut out processed foods, ensuring they eat at least 1g of fibre per 9g of carbs, stop drinking alcohol, and consume all vitamins and minerals our body needs.

If you do this, you will allow your immune system to function at its highest capability.