Healthy skin is not just ‘skin-deep’. In fact, skin health very much depends on what is happening deep inside the body, especially in our gastrointestinal tract (the ‘gut’) and the microbiota/microbiome (‘gut flora’).
There is an invisible connection that enables cross-talk and communication between these two apparently unrelated organs. Remarkably, this connection, called the ‘gut-skin axis’, was identified alongside many others in emerging evidence about the relationship between the gut and other organs in the body. An axis may be bi-directional or multi-directional (between the gut and one other organ, or multiple organs), with communication happening via connecting microbiota and immune cells. In this blog we will explore the multi-directional pathway between the immune system and the gut-skin axis, and what this means for immunity and skin health.
The Interconnection Between the Immune System, Gut and Skin
One body system and two organs. What do they have in common? Surprisingly, a lot.
All three interlock and cooperate as the body’s primary defence shield, keeping us healthy and defending the body from the outside world. Together they safeguard against changes in the body and help regulate inflammation.
Usually, we think of these functions as being specific to the immune system. However, both the gut and the skin perform similar roles. In fact, our skin is a part of the immune system, providing a first line of defence, and more than 70% of immune cells are located in the gut.
When unwanted nasties find their way into the gastrointestinal tract via the food we eat, the gut’s immune defence system kicks in. The gut has a very large surface area (around 30 m²) that is usually semi-permeable, selectively allowing the absorption of nutrients. It prevents unwelcome substances from entering and being transported to the rest of the body through: 1) an internal sticky mucous layer that acts as a trap, 2) an additional cell layer that acts as a barrier, and 3) the immune cells that live inside these layers, all of which interact with the gut’s microbiota. Likewise, the skin (with a surface area of 1.5 to 2 m²) acts as a protective barrier. It too has a microbiota, only on the outside. Interestingly, the microbiota of the gut is similar to that of the skin.
The gut and the skin share many structures and functions. They both:
- have a large surface area
- have their own microbiota
- are lined with cells that form a protective barrier
- are part of the body’s primary immune defence system
A New Understanding of the Drivers of Poor Skin Health
Based on emerging evidence, we now know that poor skin health is not just the result of an imbalance in the skin itself, but potentially in a number of body systems, especially the gut. One such imbalance, called ‘dysbiosis’, is increasingly recognised as an important trigger for many troublesome skin concerns, such as skin dryness and poor hydration. When the gut microbiota is out of balance, immunity is disrupted and low-grade inflammation can set in. The gut-skin axis has therefore become an important field of study for understanding the basis of skin health and how to address any imbalances.
How to Nurture the Gut-Skin Axis and Maintain Good Skin Health
A growing body of evidence suggests that supporting the gut microbiota by supplementing with prebiotics, probiotics, postbiotics and/or synbiotics can nourish and promote beneficial gut flora, relieve inflammation, and support skin health by relieving dryness and enhancing skin hydration.
- Prebiotics are fuel for our microbiome that promote the growth of good bacteria in and on the body (the gut and skin). They also support skin barrier function and help regulate inflammation, which in turn supports healthy skin via the gut-skin axis. Inulin is a good example: a plant-derived soluble fibre and established prebiotic.
- Probiotics are live microorganisms, or beneficial bacteria, that promote healthy gut flora and support overall gut health. They can also support skin health in multiple ways, such as by regulating the body’s inflammatory and immune responses. One such probiotic is Bifidobacterium lactis HN019, which helps improve intestinal transit time and relieve constipation.
- Postbiotics are inactivated (dead or heat-killed) bacteria sourced from beneficial bacteria. Certain strains, such as Lactiplantibacillus plantarum L-137 (formerly Lactobacillus plantarum), have been shown to relieve inflammation, enhance skin hydration and promote immune defences.
- Synbiotics combine probiotics and prebiotics, enhancing the benefits of both.
While most of us are familiar with prebiotics and probiotics, postbiotics are less well known. Here is a great example of one that helps to nurture the gut-skin-immune axis, build a resilient immunity shield and promote good skin health.
Lactiplantibacillus plantarum L-137 (HK L-137): A Postbiotic for Dry Skin
Daily intake of the heat-killed postbiotic L-137 (HK L-137) relieves dry skin by improving its ability to retain moisture, helping to maintain good skin health. It is thought that L-137 does this by increasing the skin’s production of hyaluronic acid (HA), a key substance that helps improve skin hydration. L-137 is also able to maintain healthy inflammatory responses in adults, as well as enhance immune defences.
In summary, we can support healthy immune responses, and therefore our immunity shield, as well as good skin health, by nurturing the gut-skin-immune axis, which is intricately linked via the microbiota. Pre-, pro- and postbiotics can all assist, with L-137 being particularly suitable.
About the Author | 📑
Hi, my name is Sandra. I am a naturopath, nutritionist and herbalist from the Sunshine Coast and am a Senior Consultant at Natural Product Centre.
I graduated 30 years ago and have worked in the health and wellness industry ever since. On a professional basis, I love being involved in the development of natural supplements, research and health writing and hope to make a positive difference to the wellbeing of all the consumers and readers I reach, directly and indirectly.
My hobbies include travelling, exploring new places and art galleries and creating my own art. I also love nothing more than spend time in nature and be surrounded by the beautiful local flora and fauna of the coast.
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