The gut is your gastrointestinal tract, the passageway from mouth to anus, and includes the esophagus, stomach, and intestine. The bacteria in the gut play a crucial role in health in general and skin health in particular. Many skin diseases are found alongside an altered gut microbiome. 

Research is discovering how important the microbiome is for regulating the immune system. It has a bidirectional communication pathway with the brain, thyroid, estrogen, and liver. These are all essential to optimum health and are imperative for treating melasma.

Each of our bodies contains roughly 25 meters of skin surface area. The skin is a deceptively enormous detoxification organ, covered in bacteria to the count of 10(12) (that’s 10 with twelve zeroes!). The gut pathway is an astonishing 30 square meters of surface area and contains even more bacteria than the skin, at 10(14)!  Science is discovering the importance of connecting these two surface areas with their enormous bacterial colonies, known as the gut-skin axis.

It turns out a huge proportion of your immune system is actually in your GI tract! This is a new field of study, and most dermatologists are unfamiliar with the concept. The slow but steady influx of probiotics into the beauty industry proves that the field is continuing to recognize the importance of gut health. While this is promising, as always, we must be wary of products being introduced just to take advantage of the ‘next wave’ without offering any real benefit aside from a placebo effect. There is much to learn about how to fix the gut; taking a probiotic won’t solve the problem for most people. Improving your gut health is essential to Mind Body Beauty balance. There are necessary steps for healing the gut properly.  It might just be the missing link to your chronic skin conditions. 

The Gut-Skin Axis.

Inflammation is the immune system’s defense mechanism responding to immune stimulation. The gut regulates immune function throughout the body. The gut also regulates your hormones. Estrogen and thyroid strongly depend on the gut for optimum health and balance. Immune function and hormone function are primary components of melasma and its treatment. 

Whatever the cause of your melasma, from UV damage to birth control, you will need to fix your gut to heal your skin permanently. A typical conversation in the melasma community, on forums and chat rooms, is that different causes require different treatments. In this case, I want to reiterate that no matter the reason, attention to your gut will facilitate healing your condition.

Consider that your gut status, meaning how healthy your gut is, can affect how your genes express themselves! This means that your gut can influence how your body develops a disease. Fun fact: the human genome consists of twenty-three thousand genes, and the gut has a bacterial genome of twenty-two million. It is possible to imagine that the gut takes charge of more gene expression than the human genome itself. 

The gut is vital for every single chronic skin condition. It is probably the most important thing to fix when working on skin health. Everything from acne, rosacea, eczema, and psoriasis all have a relationship that depends on gut health. 

The Gut-Brain-Skin Axis. 

The Gut-Brain Axis refers to how the gut influences brain function. It is a bidirectional pathway between the central and enteric nervous systems that connects the emotional and cognitive parts of the brain with the intestinal tract. You know that saying, “Your gut is your second brain,” well, it is. The microbiota influences neural, endocrine, hormone, immune, and humoral connections. Generally, this area is discussed regarding mental health and conditions like anxiety, depression, etc. However, we know that the skin plays an important role in this signaling pathway for many reasons. Many people with IBD, colitis and other intestinal diseases also suffer from chronic skin conditions. People with SIBO are ten times more likely to have rosacea, and 24% of Crohn’s patients have conditions like psoriasis or eczema. Celiac disease also has skin problem associations, and studies have connected gut dysbiosis with acne. We know the gut-skin connection exists. Medicine has yet to acknowledge it, though fully. 

Stress plays a vital role in the development of melasma. This can be a primary cause of melasma and a contributing factor. Stress is a vital hormone, but dysregulated stress can impact the gut and the immune system, which play a significant role in chronic skin conditions. 

The HPA which we described in the Defining Melasma article, acts directly on the skin through CRH (corticotropin-releasing hormone), which is released in the hypothalamus, ACTH (adrenocorticotropin-releasing hormone, released in the pituitary, and cortisol, which is released in the adrenal glands. ACTH shares a pathway with a~MSH (alpha melanocyte stimulating hormone), which stimulates skin pigmentation and is the primary component of melasma. When the HPA (hypothalamus-pituitary-adrenal) axis becomes dysregulated, the negative feedback loop turns on and causes overstimulation of the hormone signaling. CRH is also responsible for skin mast cells and the dilation of blood vessels, which could explain the vascular component of melasma. The skin has CRH receptors that directly influence how stress can exacerbate chronic skin conditions. Conditions like eczema and psoriasis often get flare-ups with chronic stress release. Whether you have melasma from birth control or other factors, stress will inevitably cause a flare-up, cause the condition to worsen, and can even be the root cause for some.

Immunity.

The gut regulates the body’s immune system by communicating with different immune cells in the skin. Immune cells protect from bacteria, viruses, fungi, and toxins and play a significant role in developing melasma and other chronic epidermal conditions. When trauma, toxins, and heat damage tissue, immune cells release pro-inflammatory cytokines such as histamine, bradykinins, and prostaglandins. Such chemicals are released from blood vessels and aggravate melasma.

Oxidative stress is another contributor to chronic inflammation associated with melasma. Oxidative stress is when free radicals damage DNA. It can also damage the intestinal barrier, lead to more ROS production (reactive oxygen species), and cause mitochondrial dysfunction and intestinal epithelial cell death. This can lead to a vicious cycle and a negative feedback loop. 

Langerhan cells are a dense network of immune cells located in the epidermis and the gut that significantly regulate the immune system and inflammation. 

Epithelial cells line all your organs, including your digestive tract and skin; the skin is considered epithelial tissue. Epithelial cells also contain most of an individual's melanin. It is the non-vascular part of the skin and plays a significant role in skin barrier function. 

Mast cells are located near blood vessels under the skin and intestines. Mast cells play a role in melasma’s vascular component. That is why some people notice more tiny blood vessels at the skin's surface. When small blood vessels become visual on the face, it is called telangiectasia. Mast cell activation, also associated with melasma, is an inflammatory condition where mast cells repeatedly release chemicals into the body, aka histamine. 

All three types of immune cells play significant roles in melasma, and the microbiome regulates all three in the digestive tract. Again we see the close relationship between the digestive system and the skin; their optimal balance is interdependent. 

Enough dense medical jargon. Let’s keep it simple: The microbiome supports skin health and restoration after UV exposure and/or any other type of inflammation via toxins, bacteria, fungus, etc. Gut imbalance can negatively impact skin barrier function. Pathogenic metabolites can build up in the skin and also lead to dysfunction. Intestinal dysbiosis can increase inflammatory immune cells, aka cytokines, and contribute to an ongoing cycle of systemic inflammation.

Hormones. 

Hormonal imbalances are some of the most common causes of melasma. The gut has a significant role in the neuroendocrine system called the Gut-Brain Axis. The two have a symbiotic relationship as hormone imbalances can also harm your gut. The primary hormones for melasma are cortisol, thyroid, and estrogen.

Cortisol, your stress hormone, is often discussed in terms of its relationship to the HPA axis. The HPA axis is a self-regulating stress response feedback loop. If you haven’t read the Defining Melasma article, you should visit first and get caught up on all things HPA. Dysregulated stress can influence your estrogen and thyroid function. Cortisol also heavily affects your skin health. It can cause increased oil production and makes your skin dull and dry. Cortisol lowers immune function, increases inflammation, and can deteriorate your skin barrier function. Stress can also impair gut barrier function and irritate or deteriorate the gut lining. 

Have you ever noticed when you get stressed out, your stomach hurts? Have you  noticed that when something doesn’t feel right, you can get a “gut feeling?”  Well, that’s because when the stress response kicks in, it sends the blood flow and oxygen from your gut to your brain. Chronic stress can lead to GERD, IBD, IBS, and ulcers. When under chronic stress, your digestive system may shut down. Have you ever been so worried, sad, or depressed that you lost your appetite?

Repairing your gut will lower inflammation, reduce acute and chronic stress and enhance sleep, all of which create a positive feedback loop of stress reduction. This leads to the conditions for a flourishing microbiome. The stage is then set for a microbiome that fights proactively to heal and repair the skin.

Gut Feelings. 

Sometimes I get hyper-focused on understanding medical studies and underlying causes that I forget to see the big picture. The interconnectedness of the human body and its miraculous ecosystem is genuinely astounding. Sometimes it can seem daunting to take on because of the work or understanding required to reverse chronic skin conditions. You are not alone on your journey. I have been there, and there are so many women here with you, trying to figure this out.

The most important takeaway from this article is that healing your gut is one of the most critical steps to healing your skin. Doing this will undoubtedly, give you that glow you’ve been wanting.

Be sure to check out my last article Vitamins, Minerals & Your Skin.

Feel free to ask a question or leave a comment.