Healthy Mouth, Healthier Skin: The Psoriasis and Eczema Link
Know how your Oral Microbiome may influence Psoriasis and Eczema

Usually, when we think about itchy, inflamed skin, our gums are the last thing on our minds. Most people look at creams, allergies, stress or diet. Very few look inside their mouth. Yet emerging research suggests oral health deserves attention too.
Scientists are studying how microorganisms in the mouth may interact with the immune system and influence inflammation elsewhere in the body. This developing area of research is often called the oral–skin connection. Here is what science says, explained simply, and what it could mean for you.

Your Mouth: A Living Ecosystem
The oral microbiome is the community of microorganisms living on your teeth, tongue and gums. It includes billions of bacteria from hundreds of different species. Most are normal residents of a healthy mouth. They help with early digestion, protect your gums and teeth, and keep harmful microbes in check.

Every time you talk, eat, drink and swallow, many of these microorganisms travel from your mouth into your gut. So, what happens in the mouth does not stay in the mouth. It may have effects well beyond your teeth and gums.

When the Balance Tips
However, this community can sometimes fall out of balance. Scientists call this imbalance dysbiosis. In other words, it is a shift toward more potentially harmful bacteria and fewer protective ones. A simple way to picture it:
More harmful bacteria → more inflammatory signals → effects that may reach the gut, the immune system, and possibly the skin.

Researchers are investigating whether particular microbial patterns could contribute to inflammatory skin conditions. They are one possible influence among several, alongside genetics, immunity and the skin barrier.

How Might the Mouth and Skin Communicate?
Think of the immune system as a messaging network. The leading idea is not that mouth bacteria travel to the skin and infect it. Instead, microbial signals in the mouth may influence immune activity. As a result, inflammation may be affected even far from where the microorganisms live. In other words, they may act as a remote trigger. It is important not to oversimplify this. Psoriasis and eczema do not share identical inflammatory pathways:

• Psoriasis is strongly linked to immune signals called IL-17 and IL-23. Gum disease (periodontitis) involves some of the same signals, which is one reason researchers are interested in the mouth–psoriasis link.
• Eczema (atopic dermatitis) is mainly driven by different immune signals, IL-4 and IL-13, as clinical trials of eczema treatments have shown.

Therefore, describing both conditions simply as “IL-17-driven” would be misleading. In fact, scientists are still working out how oral bacteria might influence each one. Moreover, no study has yet directly shown whether, or how, oral bacteria trigger skin inflammation in people.

What Does Research Show?
Psoriasis and eczema: genetic clues
A 2026 study in the International Dental Journal used Mendelian randomization, a method that uses natural genetic differences between people to investigate possible cause-and-effect relationships. Through this approach, the study identified suggestive links between certain oral microorganisms and inflammatory skin diseases. In particular, these included psoriasis and atopic dermatitis.

Overall, these findings offer clues about possible biological connections. However, they do not prove that oral bacteria cause an individual’s skin condition, or that changing those bacteria will improve symptoms. Similarly, although the study discusses potential immune mechanisms, it did not directly test them.

Psoriasis and gum disease: shared inflammatory markers
Psoriasis and periodontitis are both chronic inflammatory conditions. For example, a cross-sectional study looked at 60 people and measured the inflammatory markers TNF-α and IL-17A in their blood. Notably, blood levels of both markers were highest in people who had both psoriasis and gum disease. In comparison, levels were lower in people who had gum disease alone and in healthy volunteers. The researchers suggested that psoriasis may influence inflammation in the gums. Like all cross-sectional studies, it shows an association at one point in time, not cause and effect.

Eczema: Differences in oral health
In addition, a study in the February 2025 issue of the International Dental Journal compared 45 adults with atopic dermatitis with 41 people without it. Compared with this group, participants with eczema had more dental plaque and poorer oral hygiene measures. Furthermore, their oral bacterial communities were different, with more bacteria linked to oral disease and fewer linked to a healthy mouth. However, this only shows an association. In other words, it cannot establish whether oral changes contribute to eczema, whether eczema influences oral health, or whether other factors affect both.

Putting It Into Practice: What This Means for You
You cannot change your genes, but you can support a healthier oral microbiome:

• Keep your oral hygiene strong – brush twice daily, floss, and see your dentist regularly.
• Eat a balanced diet rich in whole foods – fibre, vegetables and fruits support healthy microbes; limit excess sugar.
• Support your gut and oral microbiome – what you feed your mouth; you feed your gut.
• Manage stress and get quality sleep – both affect inflammation.
• Take care of your skin barrier – follow your dermatologist’s advice on moisturizing and treatment.

Next Step: Give Oral Health a Place in Your Care
So, what should you do with this information? First, if you have psoriasis or eczema along with bleeding gums, persistent bad breath or gum discomfort, discuss your oral health with a dentist. At the same time, continue to discuss your skin concerns with your dermatologist. In addition, it helps to tell each of them about the other condition. That way, both can keep the full picture in mind when caring for you.

What Can AMMAGENOMICS Testing Tell You?
At AMMAGENOMICS, we focus on molecular insights that help you and your clinician see a fuller picture. Oral microbiome testing offers a way to explore the microorganisms present in your oral sample. Depending on the test selected:

• Targeted qPCR examines selected microbial targets.
• 16S rRNA sequencing provides a broader profile of bacterial composition and diversity.

Related tests that add context:

• Gut microbiome testing – because oral microbes travel into the gut, looking at both can give a fuller view of your microbial health.
• Inflammatory cytokine panel – measures inflammatory markers including TNF-α, IL-6, IL-10 and IFN-γ, which can help show how active inflammation is in the body.

These results can provide additional information to discuss with your dentist, dermatologist or treating clinician.

Disclaimer: This article is for education only and is not medical advice. Oral microbiome testing does not diagnose, rule out or cure psoriasis or eczema, and does not replace dental or dermatological care. Its use in guiding treatment for these skin conditions remains investigational. Results require clinical interpretation.

Curious about your oral microbiome? Contact AMMAGENOMICS to discuss available tests, sample collection, and what the results can tell you.

🌐 www.ammagenomics.com | www.010feet.com

AMMAGENOMICS — Exploring the unseen. Understanding the interconnected.

References

1. Causal Relationships Between Oral Microbiota and Inflammatory Skin Diseases. International Dental Journal. 2026. PubMed ID: 42492463. [Add authors/volume from the paper]
2. Shahin A, Leshem YA, Taieb Y, et al. Association of Adult Atopic Dermatitis with Impaired Oral Health and Oral Dysbiosis: A Case-Control Study. International Dental Journal. 2025;75(1):279–287.
3. Shared Inflammatory Mechanisms in Psoriasis and Periodontitis: A Cross-Sectional Study. Akdeniz University (ClinicalTrials.gov NCT06897722).

© Pradheep Chhalliyil, 2026. All Rights Reserved. Unauthorized copying, reproduction, distribution, or reuse is strictly prohibited.