Probiotics and the Gut-Skin Axis
Updated: Sep 28
You may have heard about the gut-brain connection, or how a troubled intestine can send signals to the brain and vice-versa, but did you know that our gut could also have an impact on our complexions too? We’ve all heard the saying ‘healthy from the inside, out’, but perhaps there is more to that than we think.
The gut-skin axis
The relationship between our gut and our skin is now commonly known as the gut-skin axis, but it was identified by scientists as early as the 1930s.1 Our gut, or digestive tract, is home to over 100 trillion bacteria, both good and bad. Collectively they’re referred to as the gut microbiota. All of us have a unique gut microbiota which is determined by a number of factors including age, diet, environment, genes and medication- for example, we know that use of antibiotics can deplete the ‘good’ bacteria. The gut microbiota have a number of roles, including metabolising nutrients from food, producing vitamin K and protecting us against intestinal infections. The gut represents almost 70% of our bodies’ entire immune system.2 It helps to maintain homeostasis throughout the body, and any imbalance can lead to inflammation, leaky gut or digestion issues, with our skin being one of the first tell-tale signs that something is wrong from rashes to breakouts, dry skin to ageing skin.
Over 70 years ago, dermatologists John H. Stokes and Donald M. Pillsbury first proposed a gastrointestinal mechanism for the overlap between depression, anxiety and skin conditions. These dermatologists connected emotional states - depression, worry and anxiety - to altered gastrointestinal tract function, changes that cause alterations to the microbial flora, which they theorised, in turn promotes local and systemic inflammation- with both rosacea and acne being inflammatory skin conditions.1
Rosacea is a common, chronic and inflammatory skin condition that causes redness and visible blood vessels on the face. It may also produce pus-filled bumps. There also seems to be a link between gut health and rosacea. A large clinical study in Denmark 3 found that a high number of adults with rosacea also had gastrointestinal disorders such as celiac disease, irritable bowel syndrome, inflammatory bowel disease, and small intestinal bacterial overgrowth.
Acne vulgaris is a chronic disease of the pilosebaceous unit that manifests clinically as non-inflammatory comedones or inflammatory papules, pustules, and nodules. Acne is particularly prevalent in western countries, a phenomenon thought to be related to an abundance of carbohydrates in the typical western diet.4
A diet of highly processed foods and refined sugars can cause poor gut function and negatively impact your skin. To improve your gut health, cutting these processed foods out as a first measure is so important. Only then can your body properly eliminate waste products in the gut.
Probiotics- what are they and how can they help?
When looking to restore the balance of our gut microbiome, probiotics are the perfect choice of defence. They are live microorganisms found in foods and supplements which can improve the ‘good’ bacteria in the body, to support our gut and immune health. Food sources include live yoghurt, kimchi, kefir, tempeh and miso.5 There are a number of strains including Lactobacillus rhamnosus, Lactobacillus casei and the yeast Saccharomyces boulardii amongst others- some we are only just learning about. As we all have unique gut microbiota, there is no ‘one size fits all’ approach when it comes to probiotics, but finding a supplement which contains a mix of different strains should help to boost your microbiome.
A 2014 press release from the American Academy of Dermatology stated that probiotics might be the best treatment for both acne and rosacea because:
· Probiotics can form a protective barrier on the skin’s surface. This can supplement the body’s primal defence system to keep out ‘bad bacteria, which prevents the microorganisms from reacting with blocked follicles. In turn, this will prevent acne.
Probiotics have been scientifically shown to actively kill ‘bad bacteria’ too. The systemic inflammation that can cause acne and related skin conditions – is also one of the reasons why probiotics can be used for various additional health issues.
The way that probiotics work ensures that the beneficial bacteria can impact the brain, gut, and skin in a simultaneous manner. Research has proven the correlations between each of these three elements, which is why using beneficial bacteria for your gut health and diet can boost skin health and appearances as a by-product.6
Research has shown that the use of probiotics to treat acne has shown improvement in the skin and a reduction of lesions within four weeks.7
You might have heard about prebiotics and are wondering how they differ to probiotics? Prebiotics are the food source for the good bacteria in our intestinal tract and can be found in fibre-rich foods such as fruit, vegetables and wholegrains. 8 You don’t need to take prebiotics for probiotics to work, but they can give them a boost.
When it comes to taking pro or prebiotics, always follow the instructions. Some are best taken first thing in the morning before eating, whilst some are recommended to eat with food. The same for storage- be sure to read whether you need to keep them in the fridge or at room temperature.
1 Bowe, W. P., & Logan, A. C. (2011). Acne vulgaris, probiotics and the gut-brain-skin axis - back to the future?. Gut pathogens, 3(1), 1. https://doi.org/10.1186/1757-4749-3-1
2 Vighi, G., Marcucci, F., Sensi, L., Di Cara, G., & Frati, F. (2008). Allergy and the gastrointestinal system. Clinical and experimental immunology, 153 Suppl 1(Suppl 1), 3–6. https://doi.org/10.1111/j.1365-2249.2008.03713.x
3 Egeberg, A., Weinstock, L. B., Thyssen, E. P., Gislason, G. H., & Thyssen, J. P. (2017). Rosacea and gastrointestinal disorders: a population-based cohort study. The British journal of dermatology, 176(1), 100–106. https://doi.org/10.1111/bjd.14930
4 Salem, I., Ramser, A., Isham, N., & Ghannoum, M. A. (2018). The Gut Microbiome as a Major Regulator of the Gut-Skin Axis. Frontiers in microbiology, 9, 1459. https://doi.org/10.3389/fmicb.2018.01459
5 Hill, C., Guarner, F., Reid, G., Gibson, G. R., Merenstein, D. J., Pot, B., Morelli, L., Canani, R. B., Flint, H. J., Salminen, S., Calder, P. C., & Sanders, M. E. (2014). Expert consensus document. The International Scientific Association for Probiotics and Prebiotics consensus statement on the scope and appropriate use of the term probiotic. Nature reviews. Gastroenterology & hepatology, 11(8), 506–514. https://doi.org/10.1038/nrgastro.2014.66
6 American Academy of Dermatology (2014). Could probiotics be the next big thing in acne and rosacea treatments?
7 Kober, M. M., & Bowe, W. P. (2015). The effect of probiotics on immune regulation, acne, and photoaging. International journal of women's dermatology, 1(2), 85–89. https://doi.org/10.1016/j.ijwd.2015.02.001
8 Cleveland Clinic (2020) Prebiotics vs Probiotics, what is the difference?