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The Gut-Skin Connection: How Your Microbiome Shapes Clear, Healthy Skin

by Valerie Polley | Apr 23, 2025 | 0 comments

If you've ever suspected that your gut health influences your skin issues, you're not imagining things. New research has started looking at the gut-skin connection—the idea that the health of your digestive system directly affects the health of your skin.

From acne and rosacea to eczema and unexplained rashes, more evidence is starting to point to gut imbalances as a possible underlying driver of chronic skin conditions. And with this emerging research, there's a new perspective on how we might be able to better manage and even prevent these skin concerns, starting with the gut.

Read on to learn about how the gut and skin are connected, what the science says about the gut-skin connection, and how you can support glowing skin from the inside out.

Gut Microbiome 101

Your gut microbiome is made up of trillions of bacteria, viruses, fungi, and other microorganisms living primarily in your large intestine. These tiny organisms play a key role in digestion, immunity, hormone balance, regulation of inflammation, nutrient absorption, and regulation of detoxification pathways—all of which can influence your skin.

When your gut microbes are in balance, your body is better equipped to repair and protect your skin barrier. But when something throws the balance off, trouble can show up on your skin.

How Gut Imbalances Show Up on Your Skin

Gut dysbiosis (when harmful microbes outweigh the beneficial ones) can manifest in a variety of skin issues. Common skin signs of gut dysbiosis include:

When your gut lining becomes compromised (a condition colloquially known as "leaky gut"), inflammatory molecules, partially digested foods, and bacteria can escape into your bloodstream. This triggers your immune system, leading to systemic inflammation that may show up in the skin.

In addition, imbalances in your gut microbes can impair the production of short-chain fatty acids (SCFAs), which help reduce inflammation and support your skin's barrier function. So, even if you're treating your skin with topical remedies, if the root cause is in your gut, those topical solutions may only offer temporary relief.

Key Mechanisms Behind the Gut-Skin Connection

Scientists think there are several key mechanisms influencing the gut-skin connection. Here are a few potential ways the gut and skin are linked.

Immune activation in the gut triggers skin inflammation

A large portion of your immune system is housed in your gut. When it's activated by dysbiosis, your body may mount an inflammatory response, some of which can present on your skin. This is one reason conditions like eczema and psoriasis are often tied to gut health.

The gut-brain-skin axis

Stress affects the nervous system, the gut, and the skin, creating a three-way communication highway called the gut-brain-skin axis. Chronic stress alters gut motility, reduces beneficial microbes, and increases gut permeability (leakiness), which can flare skin issues.

SCFAs and other gut-derived metabolites

Healthy gut microbes produce SCFAs like butyrate, which play a role in strengthening the intestinal lining and reducing inflammation. They also support the skin's lipid (fat) barrier, helping it retain moisture and resist irritants.

Scientific Studies Supporting the Gut-Skin Connection

Growing evidence from both human and animal studies supports the connection between the gut and skin:

  • A 2019 review in the Journal of Clinical Medicine reported that people with acne have a less diverse microbiome than people without acne.
  • A randomized controlled trial published in the Journal of Microbiology, Immunology and Infection showed that supplementation with Lactobacillus rhamnosus for eight weeks helped improve symptoms of atopic dermatitis in young children.
  • Another study in the Journal of Medicinal Food reported that supplementation with a combination of the probiotic Bifidobacterium longum and the prebiotic galacto-oligosaccharides (GOS) protected against photo-aging and had anti-inflammatory effects in mice.

Overall, while the research is still developing, there's a compelling case for using dietary and lifestyle strategies to improve gut health as a way to support clear, calm skin.

6 Gut-Friendly Habits for Better Skin

So, what can you do today to support your gut and improve your skin from the inside out? Start with these science-backed habits.

Eat more prebiotic and fiber-rich foods

Foods like garlic, onions, bananas, oats, asparagus, and flaxseeds feed beneficial gut bacteria, encouraging the production of anti-inflammatory compounds like SCFAs.

Reduce added sugar and ultra-processed foods

Sugar and refined carbohydrates can feed harmful gut bacteria and promote inflammation, both in your gut and on your skin. Try reducing your intake of these foods to see if you notice a difference in your skin health.

Try targeted skin probiotics

Look for probiotics containing Lactobacillus rhamnosus and Bifidobacterium longum. These strains have shown promise in reducing skin inflammation and supporting gut balance.

Manage stress

Chronic stress alters gut motility and increases intestinal permeability, which could lead to flaring of skin conditions. Incorporate stress-reducing practices like deep breathing, gentle movement, or mindful eating. 

Get enough sleep

Poor sleep is associated with changes in the gut microbiome and increased inflammation. Aim for 7 to 9 hours of quality sleep per night. Strategies like having a consistent sleep and wake time (even on weekends), keeping your room cool and dark, and avoiding electronic devices for 1 to 2 hours before bedtime can help promote restful sleep.

Stay hydrated

Water supports digestion, detoxification, and skin hydration. Try incorporating foods containing high amounts of water (like cucumbers and watermelon) and keep a water bottle with you during the day to encourage hydration.

Final Thoughts

Your skin is a reflection of what's happening inside your body, and often, your gut is at the center of that story. While it might be tempting to treat skin issues with topical products alone, looking inward to your gut health may offer longer-lasting relief.

It's important to be patient and consistent with gut support practices. The microbiome takes time to rebalance, and skin healing doesn't happen overnight. But with the right strategies, you can support healthier, clearer skin from the inside out.

Need help figuring out where to start? A registered dietitian can help you create a personalized gut-healing protocol that supports both your digestion and your skin. Click here to get in touch with us at Blue Tree Nutrition. 

Our gut microbiome (the community of trillions of microbes that live in our gut) plays a key role in maintaining metabolic and immune health. Gut dysbiosis occurs when the composition and diversity of our gut microbiome shift. This could include overgrowth of harmful bacteria or a decrease in beneficial bacteria. Gut dysbiosis has been linked to a wide range of negative health outcomes, including increased levels of inflammation and changes in metabolism.

Many people switch to non-nutritive sweeteners like sucralose, aspartame, and stevia for health reasons, and for decades, we've believed that they pass through our bodies without affecting us. But emerging research shows that these compounds interact directly with our gut microbiome and may have potential negative effects on our health. 

This article will review what we currently know about the relationship between non-nutritive sweeteners (including artificial sweeteners and calorie-free natural sweeteners) and the gut microbiome, plus practical advice for navigating sweeteners.

Sucralose

Sucralose (Splenda) is an artificial sweetener commonly used in baked goods, gums, and sugar-free beverages and is approximately 600 times sweeter than sucrose (table sugar). However, recent research has linked it to adverse health effects such as systemic inflammation, metabolic disease, and gut dysbiosis. For example, a 2022 study found that sucralose consumption increased harmful bacteria and reduced beneficial bacteria, which was associated with changes in insulin and glucose levels.

Additionally, a 2025 randomized controlled trial examining the effects of replacing added sugars with sucralose found that people with type 2 diabetes who consumed sucralose experienced reductions in both alpha diversity (the number and types of species present in a single person) and beta diversity (differences in microbial composition between people). Interestingly, the people with overweight and obesity without type 2 diabetes did not experience the same changes.

Overall, animal studies and limited human studies suggest that sucralose may trigger intestinal inflammation, likely through its effects on the gut microbiome. However, since most of the evidence we have comes from test tube or animal studies, these results should be interpreted cautiously.

Aspartame

Aspartame is another commonly used artificial sweetener that is about 200 times as sweet as sucrose. While it does contain some calories, because you don't need much of it to reach the same sweetness levels as sucrose, these calories are negligible.

Like sucralose, most of the research into the gut effects of aspartame has been done in animals. However, we do have some very small human studies. A 2022 randomized controlled trial (RCT) involving 20 healthy adults found that participants taking aspartame showed changes in both probiotic (beneficial) and pathogenic (harmful) bacteria, but the changes were specific to each individual. 

Why the differences? It's likely due to the "responder vs. non-responder" phenomenon. We all have differences in our "baseline" microbiome. While certain bacterial species are common in healthy populations, our microbiome is as unique as a fingerprint. Whether an artificial sweetener has positive or negative effects on our microbiome may depend on which species are already present in our gut, as well as on our habitual diet. This difference in responses makes it very challenging to draw firm conclusions about whether artificial sweeteners are harmful.

Stevia

Many people choose stevia because it's a "natural" zero-calorie sweetener. Studies have shown mixed results regarding the effects of stevia on the gut microbiome. For example, while some in vitro (test tube) and in vivo (animal) studies have reported potentially harmful effects of stevia on the gut microbiome, others have found no impact, and some even reported beneficial effects through inhibition of inflammatory pathways.

Additionally, a 2024 human study found that stevia had no significant effect on the gut microbiome. This highlights the importance of not forming conclusions based solely on test tube and animal studies. Overall, it appears that stevia is a potentially less-harmful alternative to artificial sweeteners like sucralose and aspartame.

Practical Advice for Navigating Sweeteners

Since the research on artificial sweeteners is still evolving, the decision to include or avoid them comes down to personal preference. Here are some tips for including them in your diet in moderation:

  • Try gradually reducing the amount you use: If you typically use two packets of sweetener in your coffee or tea, try gradually reducing to one packet. Our taste buds are highly adaptable, and you may find that one packet is sweet enough once you get used to it.
  • Check your labels: Low- or no-calorie sweeteners (such as sucralose, aspartame, and sugar alcohols like erythritol) are often hidden in low-sugar foods like protein bars, yogurt, and diet sodas. Awareness is the first step to reducing your intake.
  • Rotate your sources: If you do use artificial sweeteners, try switching up the types you use. Since different sweeteners may affect your gut microbiome in different ways, this may reduce the concentrated impact on your gut.
  • Switch to stevia: While animal and test-tube studies show mixed findings, human research indicates that stevia has a limited effect on the gut microbiome, making it a better choice for people seeking to support their gut health.

Another way to support your gut if you regularly use artificial sweeteners is to rebuild gut diversity with fiber and fermented foods, while focusing on whole-food sweeteners.

  • High fiber prebiotic foods (like legumes, whole grains, garlic, onions, asparagus, and under-ripe bananas) act as "fuel" for your healthy gut microbes. Aim to include a variety of these foods in your diet to support the microbes already in your gut.
  • Add fermented foods, like unpasteurized sauerkraut and kimchi, kefir, or kombucha, to your diet. Some fermented foods contain live, beneficial bacterial cultures, while others are rich in "postbiotics" (beneficial compounds like short-chain fatty acids, which are produced when bacteria break down prebiotics).
  • Try using whole-food sweeteners instead of artificial ones. For example, sweeten plain yogurt with vanilla extract and berries or add dates to smoothies or homemade energy bites.

Final Thoughts

Emerging research suggests that certain low- or no-calorie sweeteners, including sucralose and aspartame, may affect the gut microbiome, whereas stevia appears to have a less negative effect. While individual responses can vary with a person's unique baseline microbiome, certain artificial sweeteners may increase inflammation or reduce gut microbiome diversity.

If you need personalized support navigating sweeteners or supporting your gut health, Blue Tree Nutrition can help. Click here to get in touch!

 

 

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Hello, I am

Valerie

My name is Valerie Polley. I am a Indianapolis-based registered dietitian and owner of Blue Tree Nutrition. I consult with clients both local and far away.
I have a bachelor’s degree in nutrition from Purdue University and I have been practicing for 20 years.
I thoroughly enjoy helping clients through their gut health journey. I see a range of GI issues including, but not limited to celiac disease, IBS and SIBO. I also specialize in the FODMAP elimination diet.

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