What Is the Connection Between Gut and Skin Health?

As we age, we become increasingly aware of those fine lines that creep up around our eyes and take over areas of our faces that used to be smooth. They may be considered lines of wisdom and experience, but they’re not always welcome or easy to accept. 

Many turn to creams, serums, or even needles to help diminish the signs of aging on our skin. But what if I told you that it goes well beyond skin deep? Research is becoming increasingly clear that what happens in our gut doesn’t just stay there—it can manifest visibly on your skin. 

In this article, we’ll explore the link between gut and skin health and how probiotics may help you achieve younger-looking skin.

What Is the Gut-Skin Axis?

Your gut and skin are more alike than you might think. Here’s what they share:

• Rich blood supply and nerves for sensation
• Microbiota or communities of microbes that protect your body
• Role in the neuro-endocrine system, using hormones and nerves
• Support for your immune system as the first barrier of defense against outside environment
• A need for balance, or homeostasis, to function optimally

Research reveals a two-way link between them. What you eat and the health of your gut can affect your skin. An imbalance in the gut, known as gut dysbiosis, can show up on your skin as puffiness, redness, or pimples. 

Scientists believe the gut flora influences the skin by impacting the immune system. For example, short-chain fatty acids (SCFAs), produced by beneficial gut bacteria, play a key role. They can normalize immune responses and regulate skin functions like wound healing. 

Gut bacteria and their byproducts can travel to the skin, disrupting its balance. This affects the types of bacteria on the skin, which in turn impacts its defense mechanisms. 

Both the gut and skin have many immune cells. These cells regulate interactions with bacteria, forming a protective barrier called the “mucosal firewall” in your gut. This firewall stops bacteria from moving to places they shouldn’t be, like your lymphoid tissues, which could cause an inflammatory response in your gut and skin. 

Gut-associated lymphoid tissues (GALTs), like Peyer’s patches and lymph nodes, are crucial for this barrier. The gut microbiota helps develop GALTs, shaping the barrier function and maintaining the balance between the gut and skin. 

Overall, changes in diet, health conditions, lifestyle, and treatments can alter gut bacteria, leading to problems like thinning of the gut mucus layer and affecting immune responses. Dysbiotic microbes and toxins can travel to the skin through the bloodstream, disrupting its balance and causing skin issues.  

What Is the Skin Microbiome?

Just like your gut, your skin has its own microbiome colonized by various microorganisms, including:

• Bacteria
• Fungi
• Viruses
• Mites

Many of these are harmless or beneficial, helping to fight harmful pathogens by teaching your T-cells to distinguish good vs bad microbes. You can think of it as its very own ecosystem. 

Internal and external factors can disrupt the relationship between the microorganisms. Your genetics may make you favor one type of microorganism over another, and behaviors such as washing your hands can change the balance.

The type of bacteria found on your skin depends on location. You find lots of Staphylococcus and Corynebacterium bacteria in wet body spots like the armpits and groin. These bacteria feed on stuff in sweat and can make it stink. 

In areas of your body with lower moisture levels, such as the arms and buttocks, a diverse array of bacteria thrives. Among them are Actinobacteria, Proteobacteria, Firmicutes, and Bacteroidetes.  

The differences in skin bacteria between people vary widely. Even more so than between different body parts of the same person. 

As you age, your skin microbiome alters. A study of 37 healthy women compared the skin microbiomes of younger and older women. Older women had greater bacterial diversity on their skin. This increase in diversity was associated with decreased levels of Propionibacterium, a beneficial bacteria for the skin. 

Propionibacterium produces antimicrobial substances and short-chain fatty acids that protect your skin and boost your immune response. 

Another study profiled the skin microbiome of 495 North Americans aged nine to 78. Researchers found a wide range of variability based on:

• Demographics
• Lifestyle
• Physiological factors 

Certain bacteria, like Corynebacteria, were associated with age-related skin changes like wrinkles and spots.

How Can Probiotics Improve Skin Health and Combat Aging?

With the discovery of the link between gut and skin health, researchers began exploring the use of probiotics to improve health. While there are some human studies, it’s worth noting that for many of these connections, only animal studies are available.

These studies provide promising groundwork, though it’s important to recognize that results in animals may not always directly apply to humans.

Decrease Oxidative Stress/Sun Damage

One of the reasons our skin begins to show signs of aging is due to oxidative stress. And one of the most significant sources of oxidative stress is sun exposure. 

Reactive oxygen species (ROS) are tiny, harmful particles created by sunlight on your skin and damage your skin cells. They cause skin injury by activating the MAPK and NF-κB loop, which helps control the behavior of cells. When activated by ROS, it can increase skin aging caused by the sun.

ROS also increases the expression of matrix metalloproteinases (MMPs) in human skin. MMPs break down key proteins in the extracellular matrix (ECM), like: 

• Collagen (keeps skin firm)
• Fibronectin (helps skin cells stick together)
• Elastin (makes skin stretchy)
• Proteoglycans (hold water to keep skin moist).

While this breaking down process is a normal part of skin repair, when MMPs become overactive, it can lead to photoaging, making your skin look older

Probiotics may help prevent damage caused by ROS through antioxidant properties. They do this by producing reactive metabolites that counter oxidative stress.

An animal study explored the effects of a Bifidobacterium on skin problems caused by oxidative stress. Subjects took oral probiotics once daily for nine days while exposed to UV radiation on days six through nine.

Researchers checked for oxidative stress by measuring hydrogen peroxide levels, damaged proteins, and harmed lipids. All of these measures were significantly lower for subjects taking probiotics than those who did not.

Support Healthy Inflammatory Response

Probiotics may normalize proinflammatory cytokines. Cytokines are proteins that help manage immune responses in the body. Some trigger the immune system to defend against harmful substances. However, too much of these cytokines can cause too much inflammation.

A study conducted in a lab setting examined the effects of Lactobacillus acidophilus on UVB-exposed skin. Researchers exposed skin cells to sunlight and then treated the cells with probiotics. They measured inflammation by checking the levels of pro-inflammatory cytokines like IL-1b, IL-8, and TNF-a in skin cells.

When exposed to UVB radiation, cytokines in skin cells increased, but decreased when treated with probiotic powder. This suggests an improved inflammatory response due to Lactobacillus acidophilus.

Prevent Protein Breakdown

As mentioned earlier, various proteins comprise the extracellular matrix (ECM). It’s crucial for supporting your skin’s structure, enabling cell communication, and maintaining skin integrity and function. Some of the most well-known proteins that decrease over time and with damage are collagen and elastin.

As cells age, the supporting matrix beneath tissues weakens. This happens because fewer matrix proteins are made, while enzymes called MMPs break down more proteins. Collagen also decreases, making tissues less elastic and prone to wrinkles.

A review of studies explored the effects of probiotics on the extracellular matrix. They found that topical and oral probiotics, like Lactobacillus acidophilus and Lactobacillus plantarum, can reduce MMP expression and increase procollagen levels, helping fight skin aging.

Improve Skin Hydration

When skin is well-hydrated it seems to glow. Adequate hydration bolsters the skin’s barrier function, effectively curbing moisture loss. Interestingly, probiotics have shown promise in reducing this loss, contributing to sustained skin hydration.

A study of 110 middle-aged participants (41-59) explored the effects of Lactobacillus plantarum on skin hydration. Participants took 10 billion CFUs orally daily for 12 weeks. Researchers measured skin hydration and gloss every four weeks.

After 12 weeks, those taking probiotics had significantly more skin water content in the face and forearms than those who did not. Skin gloss was also significantly improved.

The same researchers conducted an animal study examining the effects of L. plantarum on skin hydration. They found that probiotics might improve skin hydration by supporting increased ceramide levels. Ceramides are lipid molecules in the skin’s outer layer that prevent water loss and maintain the skin’s barrier, essential for hydration and protection.

Wrinkles

Wrinkles develop as you age due to many factors. One is thinning skin and facial muscle movement. Another is UV radiation from the sun. When exposed to UVB rays, MMP-1 increases, breaking down collagen fibers and leading to wrinkles. 

Probiotics help regulate wrinkles by stopping the breakdown of collagen and reducing the activity of an MMP-1. This helps keep skin smooth and reduces wrinkles.

The same study that explored the effects of L. plantarum on skin hydration explored their effects on wrinkles. By the twelfth week of taking probiotics, participants had a significant reduction in wrinkle depth compared to those who didn’t. 

Another study explored the effect of L. plantarum on wrinkles and skin thickness. In a lab setting, researchers exposed human dermal fibroblasts to UVB radiation, the main cell type in skin connective tissue. 

Unlike untreated cells, cells treated with L. plantarum increased procollagen secretion by 32% and stopped collagen breakdown by reducing MMP-1 expression. 

L. plantarum seems to work by intervening early in the chain reaction triggered by UVB rays, preventing the increase of MMP-1. It does this by blocking JNK phosphorylation, a step at the beginning of the chain reaction that activates the harmful effects of UVB rays.  

In the same study, animals received daily oral doses of L. plantarum over 12 weeks. Researchers monitored the quantity, size, and depth of wrinkles in all subjects exposed to UV light. Those supplemented with probiotics showed a reduction in the number and severity of wrinkles compared to mice exposed solely to UV light without probiotics. 

Elasticity

The decline in skin elasticity with age results from various factors. First, there is a decline in cell division and lipid levels in keratinocytes, which make up the skin’s outermost layer. 

Additionally, there is a decrease in collagen fibers, essential for providing structure and support to the skin. Collagen is the main structural protein of the skin and plays a crucial role in maintaining its elasticity.

Finally, fiber bundles thin, and elastic fibers decrease in the dermis, the layer of skin beneath the surface. Elastic fibers contribute to the skin’s ability to stretch and recoil, allowing it to maintain shape and bounce back after being stretched.

An animal study explored the effects of probiotic Lactobacillus fermentum on aging skin. Subjects consumed probiotics orally for 12 weeks. Researchers measured skin elasticity using a micro-tensiometer to measure tensile strength.

After 12 weeks of treatment, those taking probiotics had significantly better skin elasticity than those who did not.

Which Probiotics Are Good for Skin?

Research on probiotics’ benefits for your skin includes various strains. Let’s break it down by possible benefit :

While specific strains of probiotics may offer targeted benefits, incorporating probiotics into your overall health regimen may contribute to better skin health by maintaining a healthy balance of bacteria in the gut and the skin’s surface. 

BIOptimizers has excellent sources of some of the probiotics listed above:

P3-OM contains ten billion CFUs L. plantarum OM to support a healthy gut flora.

MicroBiome Breakthrough contains a Lactobacillus blend including L. helveticus and L. rhamnosus and IgY Max antibody to support a healthy gut barrier and immune system. 

Both formulas contain prebiotics to ensure that the good bacteria in your gut are getting the food they need to thrive.

Topical Probiotics

From cleansers and moisturizers to serums, a variety of products now feature probiotics for topical use.  

A recent review study explored the current state of topical probiotics. Researchers found that topical probiotic products or skincare with probiotics face several challenges. They often lack sterile manufacturing conditions and may contain antiseptics to control germs, affecting how well the probiotics work and changing the skin’s bacteria.

The outer layer of your skin limits how much gets absorbed, making treatments tricky. Additionally, unlike products with smaller molecules, probiotic preparations need special handling to keep the bacteria stable.

Researchers advocate for the oral consumption of probiotics as a wise approach to promote skin health. Probiotics may influence the gut flora, indirectly affecting skin health.

If you’d still like to try using probiotics topically but want to avoid those commercially produced, here are some ideas:

A yogurt facial: Choose yogurt with live cultures and apply it directly to your face. Let it sit for about 15 minutes, then rinse. 

A clinical trial discovered that participants using a facial mask containing yogurt and prickly pear experienced enhanced skin moisture, brightness, and elasticity. 

Make your own probiotic moisturizer or cleanser: Break open a capsule of P3-OM and add it to your favorite skin cream, oil, or cleanser. This allows you to bypass the challenges of commercial manufacturing while still giving your skin some probiotic benefits. 

You can also make yogurt with P3OM. However, keep in mind individual responses to these yogurt and probiotic facials can vary. If you have sensitive skin, you may want to start trying it in a small  inconspicuous spot first. 

What Foods Are Good For the Gut-Skin Axis?

Focus on eating foods that feed the gut bacteria to support the gut-skin axis and give your body the support it needs for healthy skin. While it’s always important to eat a variety of foods, there are particular foods to focus on for optimal gut health. 

Fermented Foods

One way to do this is by increasing the number of fermented foods in your diet. Incorporate foods like:

• Yogurt
• Kimchi
• Sauerkraut
• Kombucha
• Kefir

Eating this can help you achieve a more diverse gut microbiota. One exception is if you don’t break down histamine well, these foods can cause skin breakouts and therefore should be avoided.

Fiber Intake

Another way is to increase your fiber intake. Fiber feeds the good bacteria in your gut. Your digestive enzymes can’t break down fiber. However, when fiber reaches your colon, it becomes food for your beneficial bacteria, promoting their growth.

Zinc

Ensuring you are getting enough zinc is also important for a healthy gut. A study of 177 schoolchildren explored the relationship between gut diversity and zinc deficiency. Those with zinc deficiency had lower microbial gut diversity than those without, meaning it may play a role in maintaining a balanced gut. 

To improve zinc levels, focus on eating zinc-rich foods like :

• Oysters
• Pumpkin seeds
• Turkey breast
• Cheese
• Shrimp
• Lentils

Learn more about increasing the good bacteria in your gut in this article. 

Vitamins A (retinol) and D

Preformed vitamins A (retinol) and D are crucial nutrients for both the skin and gut barriers, and the microbial flora that inhabit them . In the US, vitamin D insufficiency may affect 2 out of 3 people, especially those with darker complexion . Because very few foods have enough vitamin D for your daily needs, it’s a good idea to test your levels and supplement accordingly.

Frank vitamin A deficiencies are rare, although suboptimal vitamin A levels can contribute to weaker skin or gut barriers, especially if you are genetically predisposed to poor vitamin A status. For example, if you have weaker versions of the BCO1 gene, you may struggle to convert beta-carotene into retinol and need to get retinol from food .

The best sources of vitamins A and D in food include:

• Liver of all animals, including cod liver oil, beef, chicken, and pork liver
• Some organ meats like kidneys
• Fatty cuts of meat like grass-fed ribs, steaks, and pork belly
• Fatty wild-caught fish such as mackerel and salmon
• Fatty dairy products like cream and cheese
• Free-range eggs

If you cannot stomach these foods, you can try supplements or powdered organ meat products. Some of them are encapsulated so you don’t have to taste them.

Conclusion

Initial research shows promising benefits of probiotics for skin health. Beyond skin, probiotics offer broader health advantages. Don’t hesitate to incorporate them into your routine for overall well-being. 

Choose high-quality probiotics like P3-OM and MicroBiome Breakthrough for optimal support in your wellness journey.