Having a bad skin day? Don’t worry, we’ve all been there. The journey to clear skin can be a complicated and stressful one, and often the answer can lie within, or more precisely with the good bacteria living inside our gut.
Our body is home to trillions of good bacteria which keep us healthy, and a lot of them live in our gut microbiome or digestive system. The gut microbiome impacts a lot of bodily functions, but not least skin homeostasis the skin’s harmonious ability to carry out normal functions such as protection, temperature regulation and water retention.
It stands to reason then that good gut health affects your skin health, a relationship we call the gut-skin axis. Our gut health is impacted by many external and internal factors, such as the food we eat, our lifestyle, antibiotic use, genetics and stress.
When our gut microbiome is out of balance, otherwise known as gut dysbiosis, this can negatively impact our skin, leading to inflammation and infections, such as acne, and eczema. So how exactly is our gut linked to our skin, and what can we do to improve the health of both?
Which Skin Conditions Are Exacerbated By Poor Gut Health?
Acne vulgaris affects approximately 85 percent of adolescents, and there are three primary causes; oil overproduction, abnormal skin peeling, and inflammation caused by the bacteria Propionibacterium acnes. Gut microbiota can influence the chance of getting acne as gut dysbiosis can lead to inflammation in the skin.
Gut dysbiosis effects our skin barrier, increasing the permeability of the outer layer of our skin, allowing the skin barrier to be more susceptible to external influences such as bacteria and pollutants. This triggers an inflammatory response, which manifests as acne.
Some of us develop acne scars after the acne is gone, appearing as red marks and textured skin. Your gut microbiome is also essential for immunity, and helps to produce vitamins such as vitamin K, which help your skin heal wounds and bruises like acne scars, dark spots and stretch marks. Therefore, keeping your gut healthy can help avoid getting acne, and improve the healing of any scars you may already have.
Atopic dermatitis is the most common form of eczema, and is characterised by itchy, dry and cracked skin. As we have seen with acne, gut dysbiosis can affect the integrity of the skin barrier, allowing it to be affected by pollutants and bacteria. After genetic causes, a compromised skin barrier is one of the primary causes for the development of atopic dermatitis.
Atopic dermatitis is also an autoimmune disease; when our immune system mistakenly attacks our own body. There is evidence that our gut microbiome has an effect on our immunity, and while good gut health can improve our immune system, an imbalance of good bacteria caused by the typical western diet has been found to place our immune system out of balance, which could trigger conditions such as atopic dermatitis.
It is particularly the high fat and low fibre content of the western diet that has been found to change the gut microbiome, which decreases the production of short chain fatty acids, which are essential for our immunity and to prevent conditions such as atopic dermatitis. Increasing the fibre content in our diet will therefore have an anti-inflammatory effect on the skin, improving the immune system and strengthening the skin barrier.
The Effect Of Probiotics And Prebiotics
The Difference Between Probiotics And Prebiotics
A good way to look after your gut health and skin health holistically is to ensure you are taking sufficient probiotics and prebiotics every day. Probiotics are the ‘good’ bacteria that live in your gut, while prebiotics are the ‘food’ for the probiotics to survive. Both are essential for optimal skin and gut health, and can be taken in supplement form, or through the diet. Foods such as garlic, onion and leeks are great prebiotic foods, while probiotic yoghurt, kimchi and kombucha are great sources of probiotics.
Specific metabolic products of amino acids have been identified as markers of a disturbed gut microbiome, and circulate in the skin, impairing skin regeneration and reducing skin hydration. There is evidence then that probiotics can help increase skin regeneration, with a study on mice finding that the probiotic strain Lactobacillus reuteri found in probiotic supplements and foods such as cheese, accelerated wound healing in mice.
Another study found that probiotics can help increase keratin in the skin — the main protein that makes up the outer layer of the skin — as well as a protein in the skin called filaggrin which is responsible for flexibility and hydration. So not only can probiotics help increase skin regeneration, giving us fresh youthful skin, but can also have a moisturising effect.
Another way that gut health can affect our skin is through thickness. The dermal layer of the skin is the layer below the outer epidermis, and consists of collagen and elastic tissue. This layer is responsible for strength and flexibility and helps give a ‘youthful’ look to the skin.
A study on mice found that supplementation with the probiotic strain Lactobacillus reuteri, found in probiotic yoghurt, triggered increased dermal thickness, and thicker shiner hair after five months of supplementation. The strain was just as effective as a supplement form isolated from the yogurt, taken with water.
The thickening of the skin and improvement in radiance is thought to be due to the anti-inflammatory effect of a probiotic-rich diet, as ingestion of Lactobacillus reuteri has been found to reduce stress-related inflammatory responses in the skin through the gut-brain-skin axis.
Dry skin is a consequence of ageing, but can also be worsened by cold weather conditions and medications. A study on humans found that supplementation with the strain Lactobacillus brevis, found in probiotic foods, resulted in a significant decrease in water loss in the skin after 12 weeks. The hypothesis is that Lactobacillus brevis stimulates the release of the hormone serotonin in the gut, which in turn increases blood flow in the skin and boosts skin hydration.
Multiple studies have also found that another probiotic Lactobacillus plantarum improves skin hydration and has anti-photoaging effects. One study on 110 volunteers found that 12 weeks of supplementation with Lactobacillus plantarum resulted in significant improvements in skin gloss, hydration, and had significant reduction in wrinkle depth. In addition, skin elasticity improved by 21 percent after 12 weeks, suggesting this probiotic strain may have a significant anti-ageing effect on the skin.
It is well known that sun exposure is a primary cause of skin ageing and wrinkles, however it has been found that some strains of probiotics can support the restoration of skin homeostasis after sun induced UV damage. The strain Lactobacillus johnsonii protected against UV-induced skin hypersensitivity in mice after 10 days of supplementation, one study showed, while another study on humans found that 10 days of supplementation after sun exposure resulted in the recovery of skin immunity, and contributed to protecting the skin against UV damage.
4 Probiotics To Consider
Lactobacillus Reuteri: As mentioned above, the strain Lactobacillus reuteri is a great one to look out for when buying probiotics. It is included in most multi-strain probiotic supplements, and has been found to increase skin regeneration, improve skin thickness, as well as improve hair thickness and shine.
Lactobacillus Plantarum: This strain is essential for improvements in skin elasticity, hydration, and reducing wrinkle depth. 12 weeks is all you need to see a significant difference.
Lactobacillus Brevis: This probiotic strain has also been found to significantly improve skin hydration through the stimulation of blood flow in the skin.
Lactobacillus Johnsonii: This strain is particularly useful in protecting against UV-induced skin damage.
If your skin is dry, dull, flaky or if you suffer from acne, this could be a sign that you could benefit from improving your gut health. Although there are many other causes for these skin conditions, looking after your gut health is a good place to start to rule out any of the effects of an imbalanced gut microbiome.
However, looking after our gut health is not all about our appearance. A healthy gut also influences our mind, producing ‘happy’ hormones such as serotonin, boosting our mood and helping regulate our sleep. After all, when we feel good from the inside, this radiates out, giving us the most powerful glow of all.
If you would like to know what probiotic foods your diet might be lacking, or how to incorporate more gut-friendly foods into your diet, you can book an appointment with nutritionist and anti-ageing specialist, Ishika Sharma at ishikasnutrition.com