Your skin cells help protect your body from dirt and pathogens, but did you know they also contain bacteria that actively protect against solar radiation?
As we know, the composition of the microbiota regulates the intestinal barrier, modulates the immune response, influences metabolism, and produces essential compounds such as short-chain fatty acids and neurotransmitters. Dysbiosis is associated with numerous pathologies, including metabolic, autoimmune, neurodegenerative, and cardiovascular diseases, including skin diseases. Therapeutic interventions, such as probiotics, prebiotics, postbiotics, and microbiome transplantation, offer promising prospects for restoring microbial homeostasis and preventing chronic diseases. There is a clear relationship between nutrition and skin health, or nutritional dermatology.
When considering skin care, we can also consider that the microbiomes of the skin and gut communicate through the gut-skin axis, so changes that occur in one can impact the health of the other.
The skin is the largest organ in the body and extends from head to toe. The functions of the skin microbiota are multiple. Commensal microorganisms at this level form a natural protective barrier against skin colonization by pathogens, competing for space and nutrients and synthesizing antibacterial molecules (natural antibiotics, free fatty acids, cAMP) that inhibit pathogens. The microbiota stimulates the immune system by maintaining the local pro- and anti-inflammatory balance and activating local immune cells. These microorganisms regulate skin pH, maintain the integrity of the stratum corneum, control local inflammatory processes, and preserve skin homeostasis. Some microorganisms can stimulate cell regeneration processes, promoting the repair of skin lesions. A balanced skin microbiota reduces the risk of skin conditions such as acne, atopic dermatitis, psoriasis, chronic wounds, and local bacterial or fungal infections. Furthermore, the microbiota helps the skin adapt to various environmental conditions, such as variations in temperature or humidity and exposure to chemical agents. An imbalance in the skin microbiota can lead to pathological conditions such as eczema, psoriasis, and acne. The balance of skin microbiota components can be altered by different elements and dynamics, such as changes in pH levels, exposure to environmental toxins, and the use of certain skin care products. Some research suggests that certain probiotic strains and their metabolites (postbiotics) may offer benefits such as improving skin barrier function, reducing inflammation, and improving the appearance of acne-prone or eczema-prone skin. Consequently, in recent years, probiotics and postbiotics have become a popular ingredient in skin care products. It has been shown that skin health can be influenced by the gut-skin axis, and that imbalances in the gut microbiome caused by poor diet, stress, or antibiotic use can lead to skin conditions.
Vitamin D, primarily synthesized in the skin through sunlight exposure, plays a critical role in maintaining the integrity of the gut barrier and promoting a healthy microbiome. Oral probiotics are a group of live microorganisms that could alter the gut microbiota and induce a protective effect in specific skin cells by inducing various immune and inflammatory responses. For example, a probiotic composed of Lactobacillus acidophilus , Lactobacillus delbrueckii subspecies bulgaricus , and Bifidobacterium bifidum was shown to be similarly effective as minocycline 100 mg daily for acne . A significant reduction in acne lesions, modulation of skin biophysical properties, and sebum excretion rate were observed with a supplement composed of a mixture of different strains of Bacillus species. Supplementation with the probiotic strain Lactobacillus rhamnosus SP1 (LSP1) in adults with acne normalizes the cutaneous expression of genes involved in insulin signaling and improves skin appearance.
Optimizing human nutrition for skin and overall health requires whole foods with their complex phytonutrient environment, beyond the essential nutrients. Macro- and micronutrients and phytonutrients work together to produce collagen, elastin, and other proteins necessary to repair and maintain healthy skin. Antioxidant and anti-inflammatory compounds play a role in blocking harmful UV rays or ensuring that their damage is minimized. Although topical creams and other products can protect the skin from the outside, it is essential to protect it from the inside.
The literature was reviewed to determine which nutrients and phytonutrients play an important role in protecting and maintaining skin health. Key compounds were highlighted, as there is evidence to suggest their significant role in skin health: vitamin A, vitamin C, vitamin D, vitamin E, zinc, omega-3 fatty acids, polyphenols/flavonoids, copper, selenium, and silicon. In the last link, a sample daily diet for healthy skin was designed, using only whole foods, that met the daily values for vitamins and minerals and contained key compounds for skin health. The tables show the nutrient and phytonutrient content of each food, respectively. For example, green tea has numerous polyphenols and flavonoids . Grapefruit was selected because it is rich in β-carotene and contains lycopene due to its color. Grapefruit consumption is associated with higher vitamin C intake as well as an improved dietary pattern . Orange bell pepper alone meets the daily values for vitamin C . Tomato was chosen because it is a good source of lycopene and β-carotene . The herb parsley was chosen because it is a rich source of silicon and polyphenols and has one of the highest concentrations of carotenoids among the herbs. Lemon was chosen for being a rich source of vitamin C and selenium, but also contained several polyphenols. Consumption of cocoa, high in flavanols, was associated with better skin health. Milk is incredibly nutrient-dense and contains many vitamins and minerals, especially calcium, as well as zinc, selenium, and copper, which are important for skin health. The only sources of EPA and DHA in the daily diet were milk, eggs, kefir, and sockeye salmon. Eggs and sockeye salmon also provided choline. Similarly, kefir was chosen as a low-calorie animal food that provides vitamin A and selenium. Fenugreek was chosen primarily as a rich source of choline, and fenugreek extract has also been shown to be effective in reducing collagen breakdown and improving collagen production. Fenugreek is also a source of vitamin A, selenium, and silicon. Collagen is essential for the composition of the dermis, and many foods contain the amino acids necessary for its production; however, it can also be obtained in supplement form. In fact, oral administration of collagen has been found to result in a statistically significant improvement in both skin elasticity and hydration. Collagen can also be obtained from whole foods, such as fish; therefore, salmon provides an additional benefit in this skin-focused diet.
Microbes interact throughout all of Creation. No surprise not only do they have extreme importance to our internal body, but also interact and involved both inside and out of our bodies. So while hand washing, bathing, laundry, simple sanitation are all good practices for our health, the 24/7 constant marketing messaging suggesting any and all microbes are dangerous encourages many to have an obsessive focus on a false belief they are being clean. Much of this also a foundation that - We Stink. We have had for decades spray away on the armpits because - You Stink. Now we are getting what amounts to spray your whole body because - You Stink. This is not a good thing on so many levels, but it makes perfect sense not only are we in a symbiotic relationship with microbes within the body, but on the outside too. Good diets would seem to afford a healthy landscape for a balanced microbe environment likely to interact with those microbe environments inside us. Just as a Leaky Gut causes health issues, a leaky skin environment causes similar problems.
Just, contributing his insights. The gut-brain-skin axis could be involved in skin diseases. For example, increased and strong expression of substance P (a neurotransmitter and neuromodulator of the central and peripheral nervous system) is observed in both acne and intestinal dysbiosis. Substance P is known to trigger the expression of numerous proinflammatory mediators, such as those involved in the pathogenesis of acne (IL-1, IL-6, TNF-α, PPAR-γ).
The gut-brain-skin axis could also be involved in atopic dermatitis: an altered intestinal microbiota modifies the production of various neurotransmitters and neuromodulators that affect the functioning of the skin barrier and the immune system, two key parameters in the pathophysiology of atopic dermatitis.
Tryptophan produced by the intestinal microbiota causes itching, while lactobacilli and bifidobacteria inhibit these sensations. On the other hand, some researchers are interested in the bidirectional effect of the gut-brain-skin axis: the skin may act on the gut through the nervous system. Specifically, the autonomic nervous system, which includes the sympathetic and parasympathetic branches, plays a key role in this interaction. Both the skin and the gut are innervated by nerves, which can communicate with each other, influencing various processes in both locations.
Sensory receptors in the skin can detect stimuli such as temperature, pressure, or pain. This information is transmitted through the nervous system to the brain and spinal cord (central nervous system). The sympathetic nervous system (fight-or-flight) can inhibit intestinal motility and secretion, while the parasympathetic nervous system (rest and digest) generally promotes these functions. Neurotransmitters: Nerve fibers in the skin and gut release various neurotransmitters (such as norepinephrine, acetylcholine, etc.) that can affect the activity of cells and organs in both locations. Thus, we have:
1) Stress response: Stressful situations can activate the sympathetic nervous system, causing changes in both the skin (e.g., sweating, vasoconstriction) and the gut (e.g., altered motility, secretion).
2) Inflammation: Skin inflammation can trigger nervous system responses that influence gut inflammation, and vice versa.
3) Pain: Pain signals from the skin can affect gut function, and pain originating in the gut can also be perceived and modulated by the nervous system.
As we know, the composition of the microbiota regulates the intestinal barrier, modulates the immune response, influences metabolism, and produces essential compounds such as short-chain fatty acids and neurotransmitters. Dysbiosis is associated with numerous pathologies, including metabolic, autoimmune, neurodegenerative, and cardiovascular diseases, including skin diseases. Therapeutic interventions, such as probiotics, prebiotics, postbiotics, and microbiome transplantation, offer promising prospects for restoring microbial homeostasis and preventing chronic diseases. There is a clear relationship between nutrition and skin health, or nutritional dermatology.
When considering skin care, we can also consider that the microbiomes of the skin and gut communicate through the gut-skin axis, so changes that occur in one can impact the health of the other.
The skin is the largest organ in the body and extends from head to toe. The functions of the skin microbiota are multiple. Commensal microorganisms at this level form a natural protective barrier against skin colonization by pathogens, competing for space and nutrients and synthesizing antibacterial molecules (natural antibiotics, free fatty acids, cAMP) that inhibit pathogens. The microbiota stimulates the immune system by maintaining the local pro- and anti-inflammatory balance and activating local immune cells. These microorganisms regulate skin pH, maintain the integrity of the stratum corneum, control local inflammatory processes, and preserve skin homeostasis. Some microorganisms can stimulate cell regeneration processes, promoting the repair of skin lesions. A balanced skin microbiota reduces the risk of skin conditions such as acne, atopic dermatitis, psoriasis, chronic wounds, and local bacterial or fungal infections. Furthermore, the microbiota helps the skin adapt to various environmental conditions, such as variations in temperature or humidity and exposure to chemical agents. An imbalance in the skin microbiota can lead to pathological conditions such as eczema, psoriasis, and acne. The balance of skin microbiota components can be altered by different elements and dynamics, such as changes in pH levels, exposure to environmental toxins, and the use of certain skin care products. Some research suggests that certain probiotic strains and their metabolites (postbiotics) may offer benefits such as improving skin barrier function, reducing inflammation, and improving the appearance of acne-prone or eczema-prone skin. Consequently, in recent years, probiotics and postbiotics have become a popular ingredient in skin care products. It has been shown that skin health can be influenced by the gut-skin axis, and that imbalances in the gut microbiome caused by poor diet, stress, or antibiotic use can lead to skin conditions.
Vitamin D, primarily synthesized in the skin through sunlight exposure, plays a critical role in maintaining the integrity of the gut barrier and promoting a healthy microbiome. Oral probiotics are a group of live microorganisms that could alter the gut microbiota and induce a protective effect in specific skin cells by inducing various immune and inflammatory responses. For example, a probiotic composed of Lactobacillus acidophilus , Lactobacillus delbrueckii subspecies bulgaricus , and Bifidobacterium bifidum was shown to be similarly effective as minocycline 100 mg daily for acne . A significant reduction in acne lesions, modulation of skin biophysical properties, and sebum excretion rate were observed with a supplement composed of a mixture of different strains of Bacillus species. Supplementation with the probiotic strain Lactobacillus rhamnosus SP1 (LSP1) in adults with acne normalizes the cutaneous expression of genes involved in insulin signaling and improves skin appearance.
Optimizing human nutrition for skin and overall health requires whole foods with their complex phytonutrient environment, beyond the essential nutrients. Macro- and micronutrients and phytonutrients work together to produce collagen, elastin, and other proteins necessary to repair and maintain healthy skin. Antioxidant and anti-inflammatory compounds play a role in blocking harmful UV rays or ensuring that their damage is minimized. Although topical creams and other products can protect the skin from the outside, it is essential to protect it from the inside.
The literature was reviewed to determine which nutrients and phytonutrients play an important role in protecting and maintaining skin health. Key compounds were highlighted, as there is evidence to suggest their significant role in skin health: vitamin A, vitamin C, vitamin D, vitamin E, zinc, omega-3 fatty acids, polyphenols/flavonoids, copper, selenium, and silicon. In the last link, a sample daily diet for healthy skin was designed, using only whole foods, that met the daily values for vitamins and minerals and contained key compounds for skin health. The tables show the nutrient and phytonutrient content of each food, respectively. For example, green tea has numerous polyphenols and flavonoids . Grapefruit was selected because it is rich in β-carotene and contains lycopene due to its color. Grapefruit consumption is associated with higher vitamin C intake as well as an improved dietary pattern . Orange bell pepper alone meets the daily values for vitamin C . Tomato was chosen because it is a good source of lycopene and β-carotene . The herb parsley was chosen because it is a rich source of silicon and polyphenols and has one of the highest concentrations of carotenoids among the herbs. Lemon was chosen for being a rich source of vitamin C and selenium, but also contained several polyphenols. Consumption of cocoa, high in flavanols, was associated with better skin health. Milk is incredibly nutrient-dense and contains many vitamins and minerals, especially calcium, as well as zinc, selenium, and copper, which are important for skin health. The only sources of EPA and DHA in the daily diet were milk, eggs, kefir, and sockeye salmon. Eggs and sockeye salmon also provided choline. Similarly, kefir was chosen as a low-calorie animal food that provides vitamin A and selenium. Fenugreek was chosen primarily as a rich source of choline, and fenugreek extract has also been shown to be effective in reducing collagen breakdown and improving collagen production. Fenugreek is also a source of vitamin A, selenium, and silicon. Collagen is essential for the composition of the dermis, and many foods contain the amino acids necessary for its production; however, it can also be obtained in supplement form. In fact, oral administration of collagen has been found to result in a statistically significant improvement in both skin elasticity and hydration. Collagen can also be obtained from whole foods, such as fish; therefore, salmon provides an additional benefit in this skin-focused diet.
https://www.frontiersin.org/journals/cellular-and-infection-microbiology/articles/10.3389/fcimb.2022.834135/full (2022).--
https://www.mdpi.com/2079-6382/12/12/1698 (2023).--
https://www.tandfonline.com/doi/full/10.2147/JIR.S441100#abstract (2024).—
https://www.mdpi.com/2227-9059/13/4/791 (2025).--
https://www.mdpi.com/2076-2607/13/4/868 (2025).--
https://www.mdpi.com/2076-2607/13/4/948 (2025).--
https://www.mdpi.com/2072-6643/17/1/60 (2025).--
Microbes interact throughout all of Creation. No surprise not only do they have extreme importance to our internal body, but also interact and involved both inside and out of our bodies. So while hand washing, bathing, laundry, simple sanitation are all good practices for our health, the 24/7 constant marketing messaging suggesting any and all microbes are dangerous encourages many to have an obsessive focus on a false belief they are being clean. Much of this also a foundation that - We Stink. We have had for decades spray away on the armpits because - You Stink. Now we are getting what amounts to spray your whole body because - You Stink. This is not a good thing on so many levels, but it makes perfect sense not only are we in a symbiotic relationship with microbes within the body, but on the outside too. Good diets would seem to afford a healthy landscape for a balanced microbe environment likely to interact with those microbe environments inside us. Just as a Leaky Gut causes health issues, a leaky skin environment causes similar problems.
Just, contributing his insights. The gut-brain-skin axis could be involved in skin diseases. For example, increased and strong expression of substance P (a neurotransmitter and neuromodulator of the central and peripheral nervous system) is observed in both acne and intestinal dysbiosis. Substance P is known to trigger the expression of numerous proinflammatory mediators, such as those involved in the pathogenesis of acne (IL-1, IL-6, TNF-α, PPAR-γ).
The gut-brain-skin axis could also be involved in atopic dermatitis: an altered intestinal microbiota modifies the production of various neurotransmitters and neuromodulators that affect the functioning of the skin barrier and the immune system, two key parameters in the pathophysiology of atopic dermatitis.
Tryptophan produced by the intestinal microbiota causes itching, while lactobacilli and bifidobacteria inhibit these sensations. On the other hand, some researchers are interested in the bidirectional effect of the gut-brain-skin axis: the skin may act on the gut through the nervous system. Specifically, the autonomic nervous system, which includes the sympathetic and parasympathetic branches, plays a key role in this interaction. Both the skin and the gut are innervated by nerves, which can communicate with each other, influencing various processes in both locations.
Sensory receptors in the skin can detect stimuli such as temperature, pressure, or pain. This information is transmitted through the nervous system to the brain and spinal cord (central nervous system). The sympathetic nervous system (fight-or-flight) can inhibit intestinal motility and secretion, while the parasympathetic nervous system (rest and digest) generally promotes these functions. Neurotransmitters: Nerve fibers in the skin and gut release various neurotransmitters (such as norepinephrine, acetylcholine, etc.) that can affect the activity of cells and organs in both locations. Thus, we have:
1) Stress response: Stressful situations can activate the sympathetic nervous system, causing changes in both the skin (e.g., sweating, vasoconstriction) and the gut (e.g., altered motility, secretion).
2) Inflammation: Skin inflammation can trigger nervous system responses that influence gut inflammation, and vice versa.
3) Pain: Pain signals from the skin can affect gut function, and pain originating in the gut can also be perceived and modulated by the nervous system.
https://pubmed.ncbi.nlm.nih.gov/27554239/ .---
https://pubmed.ncbi.nlm.nih.gov/30042740/ .--
https://pubmed.ncbi.nlm.nih.gov/29949831/ .---