Intestinal tract and skin

In microbiome research, the term axis (eng – axis) is used, as a designation that connects the microbiome with a specific part of the body and between them is determined by communication with internal signaling pathways.

I myself have the most experience in practical targeting of the intestinal skin axis, because my first job as a clinical nutritionist in 2016. was, prof. Jāņas Īša Aesthetic Dermatology Clinic. There, I also had to accept and advise, mainly, patients with various skin diseases, which made me interested in how to help solve the underlying cause of the disease. Around 2016 In the 1990s, the first studies describing the gut-skin axis appeared in the scientific literature, and upon further investigation I realized that the health of our digestive tract is closely related to the health of the skin.

The beginnings of such a connection can be traced back to 1930, when John H. Stokes and Donald M. Pillsbury described a theory that points to a reciprocal relationship between emotional states, gut microflora, and systemic and skin inflammation.

Nowadays, the gut-skin axis is often combined with the gut-brain axis, but in this blog the focus is on the connection between the gut and the skin. 

Understanding the gut-skin axis

In the past 10 years, research in the industry has supported the gut-skin axis hypothesis, which is being explored in depth to understand and target this axis.

The gut-skin axis is an internal two-way communication between the body and the skin using biochemical and physiological interactions. This axis is influenced by the immune system, hormones and, of course, nutrients, which combine to determine the state of skin health.  These metabolic signaling pathways are coordinated by the gut microbiome.Understanding the gut-skin axis opens up new opportunities to treat and prevent a variety of skin conditions, from common problems such as acne eczema (atopic dermatitis) to more complex conditions such as psoriasis and rosacea. This axis is based on the understanding that different communities of microorganisms live in our gut and skin, which interact to affect the human body. The results of this interaction are visible on human skin affecting its appearance, barrier function and homeostasis.

• Nutrient absorption vitamins (A,C,D,E), minerals (zinc, selenium), proteins and fatty acids directly affect the appearance of the skin and the formation of collagen in it.
• Immune response because the intestinal tract contains about 80% of human immune cells. Unfavorable changes in the intestinal tract cause systemic inflammation, which aggravates skin diseases.
• Detoxification, the intestines play an important role in the detoxification of harmful substances from the body. Inefficiency in this process can lead to a build-up of toxins, which can manifest as skin problems such as rashes.
• Hormonal Metabolism The gut helps metabolize hormones and imbalances can affect the skin. For example, overgrowth of certain bacteria can cause increased activity of enzymes (beta-glucuronidase) that convert androgens (testosterone) into active forms. Increased enzyme activity can lead to higher levels of free androgens circulating in the bloodstream. When these androgens enter a more active form, they enter various body tissues, including the skin. In the skin, androgens stimulate the sebaceous glands to produce more sebum (an oily substance produced by the sebaceous glands). Increased production of sebum can clog pores, resulting in a favorable environment for skin bacteria C. Acnes for development. This bacteria eats the sebum and its excessive reproduction in the pores contributes to the development of acne.

The role of the gut microbiome in skin health

The human microbiome consists of trillions of microorganisms, including bacteria, viruses, fungi and other microorganisms that live in the human body and on its surface, both in the intestinal tract and on the skin. The connection between the gut microbiome and various skin diseases has been studied. For example, people with liver, eczema, psoriasis or rosacea are often prone to changes in the intestinal microbiome - a change in the proportion of bacterial species, as well as a deviation from their intended location (for example, those bacteria that should multiply in the large intestine colonize the small intestine). An imbalance of gut bacteria is called dysbiosis, the effects of which can be seen on a person's skin.

The basis of dysbiosis is the formation of systemic (long-term) inflammation. When the gut microbiome is out of balance, it can disrupt the intestinal barrier, leading to what is known as "leaky gut."  The area of ​​the human intestinal tract is about 400 m2, which corresponds to two tennis courts in real life. The large area is achieved because there are 3,000 densely arranged microvilli at the top of the intestinal cell, the main function of which is the absorption of nutrients. Intestinal shunts are closely related to each other with cell junction contact (jugules), whose main task is to prevent the transport of foreign molecules between cells. In the case of dysbiosis, there is an increased loosening of these intercellular contacts and, therefore, the entry of unwanted substances into the body's internal environment.

This leakage allows fragments of pathogenic bacteria, such as lipopolysaccharides (LPS) from gram-negative bacteria, to enter the submucosa and further into the bloodstream, triggering a systemic immune response that leads to inflammation.

This inflammatory response is not limited to the gut; it can also affect the skin, contributing to or exacerbating conditions such as acne, eczema and psoriasis. These skin conditions are characterized by inflammation and are often more severe in people with signs of gut dysbiosis.

The gut microbiome plays a crucial role in the development and education of the immune system. The diversity of microbes in the gut is essential for training immune cells to distinguish between harmless substances and potential threats. However, when the balance of the gut microbiome is disturbed, it can lead to an excessive or misdirected immune response.

For example, in conditions such as atopic dermatitis (eczema), the immune system overreacts to environmental allergens or triggers, causing skin inflammation. Similarly, in psoriasis, an autoimmune skin condition, an overactive immune response results in a rapid turnover of skin cells, leading to the characteristic scaly patches.

The role of the microbiome in nutrient absorption

The role of the gut microbiome in nutrient absorption is critical to maintaining healthy skin. Vitamins, minerals and antioxidants that support skin health, including vitamins A, C, E, zinc and selenium, are absorbed in the gut. An unhealthy gut can cause malabsorption of these nutrients, which can lead to dull skin, increased vulnerability to UV damage, and delayed wound healing.

In addition, short-chain fatty acids (SCFAs), which are produced when gut bacteria ferment prebiotics, have been shown to have a positive effect on skin health. IKT strengthens the skin barrier, reduces inflammation and prevents the growth of pathogenic bacteria on the skin.

Short-chain fatty acids are used as a source of energy in intestinal cells, and also reduce intestinal pH, thus suppressing the development of malignant bacteria. The main short chain fatty acids are acetate, propionate and butyrate.

The bi-directional axis between gut and skin highlights the importance of maintaining a healthy gut microbiome for healthy and strong skin.

Factors affecting the gut-skin axis

Understanding the elements that affect the gut-skin axis is critical for anyone looking to improve their skin health by aligning their digestive system. A number of key factors, including diet, stress, sleep and lifestyle choices, play an important role in the balance of our gut microbiome and therefore the condition of our skin.

The Importance of Nutrition

The food we consume plays a direct role in influencing our gut microbiome. Some of the basic nutrients and biologically active substances are not digested and absorbed in the small intestine, they move further and our microbiome bacteria use them as a food source. Human dietary choices determine the composition of the microbiome, or the ratio of our probiotic to pathogenic bacteria. This ratio of bacteria is figuratively like a mirror of internal health that can be seen on our skin.

A diet rich in a variety of plant-based foods is recommended. It is desirable to eat at least 30 different types of fruits and vegetables per week, choosing a colorful assortment to prevent monotony. This diversity not only feeds a broad spectrum of beneficial bacteria, but also provides a broad spectrum of nutrients and phytochemicals that support gut health.

In addition to plant-based foods, a balanced intake of complete proteins and healthy fats is essential. Foods high in antioxidants, omega-3 fatty acids, fermented foods containing probiotic bacteria and prebiotic fiber are especially valuable. These nutrients create a healthy environment that encourages the growth and development of beneficial gut bacteria.

Observing variety strengthens the intestinal barrier and reduces inflammation; it also provides essential nutrients for glowing, healthy skin. By feeding our gut microbiome with targeted nutrients, we can improve our overall health and very visibly improve the appearance of our skin.

Effects of stress and sleep on the gut microbiome and skin

Chronic stress and insufficient sleep significantly affect gut health and microbiome balance. Stress activates the body's stress response system, especially the hypothalamic-pituitary-adrenal axis. This results in the release of stress hormones such as cortisol, which can impair gut barrier function, contributing to leaky gut syndrome and increasing systemic inflammation. Likewise, poor sleep quality, or insufficient sleep, can disrupt the gut microbiome, affecting both gut and skin health.

Lifestyle and environmental factors

Lifestyle, including smoking, alcohol consumption and lack of physical activity, affects the gut-skin axis. Smoking and excessive alcohol consumption are known to negatively alter the gut microbiome and increase oxidative stress, which causes skin aging and worsens the symptoms of skin diseases. On the other hand, regular physical activity can improve the diversity of the gut microbiome and promote skin health by improving circulation and nutrient delivery to the skin.

Environmental factors such as pollution and exposure to poor quality skin care products can disrupt the skin microbiome and skin barrier function. It is important to choose gentle, non-irritating skin care products and minimize exposure to environmental toxins, thus helping to protect the skin barrier and support the gut-skin axis.

Protective measures:

• Use antioxidant-rich skin care products: Products containing vitamins C and E can help neutralize free radicals before they damage the skin.
• Regular cleansing: Gently washing your face twice a day removes pollutants that have settled on the skin's surface.
• Skin barrier-enhancing moisturizers that strengthen the skin barrier will prevent harmful substances from penetrating into the deeper layers of the skin.

In most common skin conditions related to gut health.

Recognizing the signs of an imbalanced gut-skin axis is the first step towards rebalancing and achieving healthier skin. Various skin conditions and symptoms can indicate gut health issues.

Acne: While acne is often linked to hormonal changes and external skin care practices, recent research links gut health to acne severity. An imbalanced gut microbiome can lead to increased inflammation, which can aggravate the liver.

Eczema (Atopic Dermatitis): Eczema flare-ups are associated with an overactive immune response that can affect gut health. A reduction in the diversity of the gut microbiome has been observed in people with eczema, suggesting a link between gut health and this skin condition.

Psoriasis: Psoriasis is an autoimmune condition that causes a rapid build-up of skin cells, causing scales on the surface of the skin. The inflammation that causes psoriasis may also stem from gut dysbiosis, suggesting a link between gut health and autoimmune skin diseases.

Rosace: This condition is characterized by redness and visible blood vessels on the face. Recent research suggests a possible link between rosacea and small intestinal bacterial overgrowth (SIBO), a condition associated with an overabundance of bacteria in the small intestine, pointing to a role for the gut in this skin disorder.

Recognizing signs of imbalance

In addition to specific skin conditions, other symptoms may indicate an imbalanced gut-skin axis:

• Digestive problems: Frequent bloating, gas, constipation or diarrhea can indicate intestinal dysbiosis, which can also affect skin health.
• Food sensitivities: Food sensitivities or intolerances can be a sign of a disrupted gut barrier, which is linked to skin health.
• Fatigue and clouding of consciousness (brain fog): These symptoms are seen in association with gut dysbiosis and indicate systemic inflammation that can affect skin clarity and health.

Recognizing these signs is critical to taking steps to balance your gut microbiome and improve skin health.

Practical Tips for Balancing the Gut-Skin Axis

Balancing the gut-skin axis requires a holistic approach that includes diet, lifestyle changes, and skin care practices that support both gut and skin health. This section provides practical tips to help you promote a healthy gut microbiome, which in turn leads to clearer, healthier skin.

Tip	Action	Benefits
Follow a skin-friendly diet	Vary your diet: Eat at least 30 different fruits and vegetables a week.	Provides vitamins, minerals and antioxidants that support skin health.
	Omega-3 fatty acids: Include sources such as salmon, chia seeds and walnuts in your diet.	Reduces inflammation in the body, which is good for both the gut and the skin.
	Limit sugar and processed foods: Avoid sugar and processed foods.	Reduces inflammation and the negative effects on gut health that affect the skin.
Promote a healthy gut microbiome	Prebiotics: You eat fiber-rich foods like garlic, onions, dandelion leaves, artichokes, chilled potatoes.	Supports the growth and reproduction of beneficial intestinal bacteria
	Fermented products: kefir, buttermilk, sauerkraut, kimchi	Promotes microbiome diversity
	Keep hydrated: Drink plenty of water. 0.30 - 0.35 ml/kg	Ensures the health of the intestinal mucosa and the elimination of toxins
Follow a gentle skincare routine	Avoid overwashing: Don't wash your skin too often.	Prevents skin microbiome imbalance
	Choose non-irritating products: Choose skin barrier strengthening and chemically non-aggressive products.	Supports skin health by avoiding irritation and damage.
	Moisturize regularly: Keep skin well hydrated.	Maintains skin barrier function, protecting against pathogens and environmental damage.
Manage stress and ensure quality sleep	Stress reduction: Engage in stress-reducing activities such as meditation and hobbies.	Reduces the effects of stress on gut and skin health.
	Prioritize sleep: Practice good sleep hygiene.	Supports gut health and allows skin to regenerate and regenerate.
Regular physical activity	Exercise: Engage in regular, moderate physical activity.	Improves blood circulation, which helps gut and skin health by promoting the elimination of toxins and the supply of nutrients to the skin.
Deliberate use of substances	Limit alcohol and avoid smoking: Reduce alcohol consumption and avoid smoking.	Reduces inflammation and oxidative stress, benefiting gut and skin health.
Follow up to changes in skin and gut health	Keep a journal: Keep track of your diet, lifestyle changes, and skin condition.	Helps identify effective strategies for balancing the gut-skin axis and evaluate improvements.

Taking a holistic approach to health that takes the gut-skin axis into account can greatly improve both gut health and skin appearance. It's a testament to the power of our bodies' interconnected systems and the benefits of comprehensive, informed care for our health.

References:

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