The skin is a great barometer of what is going on inside the body. If your skin is irritated, inﬂamed or congested, chances are high that there may be an imbalance in your gut.
Our skin is our body’s largest organ; it is one of the major systems by which the body expels toxins and waste and is our ﬁrst line of defence against harmful bacteria and pathogens. Almost all skin conditions are linked to gut health but diagnosing whether or not your skin condition is caused by digestive issues can be tricky. Sometimes the connection is obvious – for example, if drinking milk triggers indigestion, hives, a rash or eczema. Other times, the connection between our gut and our skin complaint can be more difficult to spot.
How does gut health affect the skin?
In the same way our gut is in constant conversation with our brain, our gut has an intimate dialogue with our skin via the gut–skin axis. This pathway allows the gut and skin to interact with one another, mainly via the microbiome.
Many skin conditions have similar symptoms to gut conditions and the two are often closely linked and inﬂuenced by one another. So, if our gut is out of balance, irritated or inﬂamed, our skin is one of the ﬁrst places to exhibit symptoms.
Research shows that up to 34 per cent of people suffering from irritable bowel syndrome (IBS) exhibit skin manifestations. Leaky gut or intestinal permeability can mean that our body is unable to absorb and use key nutrients, vitamins and minerals that are essential for strong, healthy skin. At the same time, if our gut is ‘leaky’ and LPS (endotoxins) are able to escape into our bloodstream, they are sent to the liver for processing. This places extra burden on the liver, which is already dealing with our normal metabolic wastes and environmental and dietary chemicals. When the liver is overburdened, our skin takes on the responsibility of having to eliminate some of these toxins.
Research shows that our gut health, as well as stress, can negatively impact the skin’s protective antimicrobial barrier and make skin conditions worse.
To heal the skin, it’s essential that you ﬁrst heal the gut, fertilising it as you would a garden with essential nutrients and beneﬁcial bacteria. More and more research supports the use of probiotics in the treatment of skin conditions, and these include species and strains from the genera of Bifidobacterium, Lactobacillus and Streptoccocus.
Following are some common skin conditions that may be linked to the state of your microbiome and gut health.
Unfortunately, acne and pimples don’t discriminate, and, for many, they can be a source of embarrassment. Acne is a complex condition, so it’s important to understand the underlying causes – they can either be hormonal or digestive, or a combination of both.
Hormonal acne: Raised hormone levels, or sensitivity to testosterone or other androgens, commonly contributes to acne. Too much testosterone in the body (or a sensitivity to it) stimulates sebaceous glands in the skin, causing oil production and clogged pores. Although this often occurs during puberty, it can also affect women mid-cycle or around their period when hormonal concentrations shift rapidly and oestrogen levels drop. Another acne-triggering hormone is cortisol, our stress hormone, which can affect the balance of bacteria in our gut, suppress our immune system and cause skin inﬂammation – enter acne.
Digestive acne: The close link between gut health, hormones and acne is an interesting one. Oestrogen and progesterone, for example, can affect the speed at which food is digested and moved along the digestive tract. This is why women, at various stages of their cycle, can experience bloating, diarrhoea and/or constipation. The gut also plays a key role in how oestrogen is eliminated by the body. When the elimination pathways are slowed down because of constipation, or the liver is overburdened due to a high level of toxins in the blood stream, oestrogen metabolism and elimination can be compromised, and this can easily lead to hormonal imbalances.
Oestrogen dominance is a common condition that many women experience and the symptoms can worsen in the second half of their menstrual cycle. It essentially means that their oestrogen levels are too high in comparison to their progesterone. This can cause acne, along with premenstrual bloating, cramping, mood swings, sluggish metabolism, headaches, tender breasts and sugar cravings.
Other gut disorders, such as leaky gut and SIBO, also have close links to acne. SIBO is ten times as prevalent in people with acne, and stress-induced leaky gut may contribute to local skin inﬂammation, which is seen in people with acne. This cycle can be self-perpetuating, as an imbalance of bacteria or leaky gut can cause inﬂammation and malabsorption issues – meaning the skin isn’t getting all the essential nutrients it needs.
Rosacea is a chronic inﬂammatory skin condition characterised by redness or ﬂushing, particularly over the cheeks and nose.
Like with most skin conditions, there can be several triggers for rosacea: diet (hot and spicy foods, alcohol and caffeine) as well as hot temperatures or sun exposure, allergies, exercise and stress. Studies suggest that rosacea is also closely linked to gastrointestinal disorders and our intestinal bacteria.
One study showed that patients with rosacea symptoms are also 13 times as likely to have SIBO.
Those who have suffered from eczema will understand just how complex, painful and debilitating it can be. This chronic skin condition can manifest as itchy, dry, patchy, or red skin and can cause immense distress. While there are thought to be countless triggers, the underlying cause of eczema is often leaky gut or food allergies and intolerances.
Treatment, however, is not as easy as simply eliminating trigger foods. It is important to support immune function and a healthy inﬂammatory pathway.
Gut health and microbial diversity also play a major role in the manifestation of eczema, also known as atopic dermatitis, as leaky gut and reduced microbial diversity can result in a weakened immune system – and a greater risk of skin inﬂammation and damage to the skin’s protective barrier.
This chronic autoimmune condition can cause dry, cracked, scaly and patchy skin.
Like eczema, psoriasis is thought to be linked to leaky gut, because when endotoxins and other compounds leak through the gut wall, the body stages an attack, triggering an inﬂammatory response.
Keratosis pilaris (KP) is a common skin condition – often referred to as ‘chicken skin’ – that appears as white or red bumps on the backs of the arms, thighs, buttocks, and sometimes the face. It is the result of a build-up of keratin (the protein that protects the skin), which blocks the hair follicle, resulting in lumps and bumps.
While there’s no deﬁnitive cause – and genetics may play a role – gut health is also a key factor, as many experts believe that keratosis pilaris is a result of nutrient deﬁciencies and malabsorption issues.
Vitamin A is an important nutrient for a smooth, glowing complexion as it plays a major role in the healthy keratinisation of skin cells. Those with KP are often deﬁcient in it.
Likewise, if you are struggling with malabsorption issues and have an essential fatty acid deﬁciency, you may be more prone to keratosis pilaris, as fatty acids are essential for combating skin inﬂammation. There is also a link between KP and gluten intolerance.
Our gut microbes do not age the way we do, per se. Our microbiome changes based on our lifestyle choices, diet and medications. As we get older, our gut microbes’ capacity to produce anti-inﬂammatory short-chain fatty acids declines. This is because of our reduced capacity to support them due to changes in our bodies as we age, including an irregular transit time, reduced appetite and nutritional status.
Changes in the microbiome can result in dysbiosis, which has been linked to a range of age-related conditions and low-grade chronic inﬂammation. Low-grade chronic inﬂammation signiﬁes one of the most consistent biologic features of ageing – and one of the main drivers for premature ageing of the skin and body. Our gut microbiota may be associated with inﬂammageing (ageing caused by inﬂammation), triggered by gut dysbiosis and weakened intestinal barrier function.
Pre-clinical studies have shown age-related deterioration of the gut barrier can occur, along with increased intestinal permeability and changes to the way the muscles of the digestive tract function.
While we can’t prevent the process of ageing, by promoting a healthy gut and gut microbiome, we may be able to slow down and reduce its negative effects.
What about polycystic ovarian syndrome and acne?
Polycystic ovarian syndrome (PCOS) is a condition that causes women to have higher than normal ratios of androgens (male hormones).
Genetics can be a contributing cause, and insulin resistance and inflammation can be symptoms, as well as irregular menstrual cycles, male-pattern hair growth, weight gain, fertility issues, headaches and acne. If you suspect you have PCOS, chat with your GP about undergoing more rigorous hormonal tests.
This is an edited extract from Carla Oates’ new cookbook ‘The Beauty Chef Gut Guide’ (published by hardie grant Books RRP $39.99AU) available online here and leading bookstores.