What Is the Skin Barrier?

Our skin isn’t just for looks. It plays a big role in keeping our body safe from the outside world. If you were to take a closer look at the skin you would find three layers: the epidermis (outermost layer), dermis (middle layer), and hypodermis (bottom layer). The epidermis is where you’ll find the skin barrier.

SKIN BARRIER COMPONENTS

• Physical layer (aka the stratum corneum): outermost layer of the skin that protects against water loss and irritants in the environment. One of the most important components of this layer is the lipid (or fat) barrier – a layer of dead skin cells called corneocytes with a lipid mixture in-between holding them together. This is what helps our skin retain moisture, and control what’s allowed in and out of the skin.
• Chemical layer: found throughout the physical layer and contains defense chemicals, natural moisturizing factors, and components that help make the skin acidic (a healthy skin pH is between 4-6).
• Antioxidant layer: co-antioxidants (e.g., vitamin c, CoQ10) fights against oxidative damage and free radicals from the environment.
• Skin microbiome: comprised of living organisms that help keep our skin healthy. There is an ecosystem of good, bad, and commensal bacteria, viruses, and fungi that normally live on our skin.
• Immune layer: contains cells that are on alert for signs of danger (e.g, a break in the skin barrier) and ready to respond.

Skin Barrier Dysfunction and Acne

When it comes to the skin barrier, we have internal factors at play (e.g., aging and genetics) and external factors, including improper skin care use, exposure to skin irritants/allergens, occupational exposures, environmental conditions, and lifestyle choices that can cause damage. When our skin barrier isn’t functioning optimally it can show up as skin dryness, flakiness, itching, redness/irritation, and an increased risk of infection.

With regards to acne, studies show that skin barrier dysfunction is associated with acne-prone skin.

1. There is a loss of diversity with the skin microbiota (aka dysbiosis) in acne patients. We normally have a variety of good, bad, and commensal bacteria that reside on our skin. Cutibacterium acnes is one of those bacteria and is known for being associated with acne. However, research tells us that there are actually different subtypes of C. acnes and not all of them promote acne. For example, C. acnes subsp. defendens has been shown to play a beneficial role in skin health while C. acnes subsp. acnes has been shown to induce inflammation and generate reactive oxygen species (ROS cause damage to cells). It was normally thought that acne was a result of an overgrowth of C. acnes, but now studies show that it actually results from a loss of diversity and imbalance of C. acnes subtypes.
2. There is also increased skin barrier permeability in acne patients. Normally our skin has low permeability and blocks foreign substances from passing through. This is very similar to our intestinal lining which is semi-permeable and under healthy circumstances will only allow small molecules to pass through and into the bloodstream. With the skin barrier in acne patients we know that there is a lack of ceramides in the lipid (aka fat) layer of the skin. This leads to increased transepidermal water loss (TEWL) which can result in dry skin.

Also, some studies show that certain topical treatments commonly used for acne (e.g., benzoyl peroxide, topical retinoids, oral isotretinoin) can impair skin barrier function by increasing TEWL, inflammatory skin changes, and skin sensitivity.

Natural Skin Barrier Support

If you’ve been struggling with acne and conventional acne treatments, then looking into supporting the skin barrier may be worthwhile. Here are a few things to consider for a healthy skin barrier.

LIFESTYLE CHOICES MATTER

• Focus on a variety of colorful fruits and vegetables. A diverse diet is important for a healthy gut microbiome. Studies show that there is a direct correlation between our gut microbiome and skin microbiome. If we have dysbiosis and increased intestinal permeability (aka “leaky gut”), then it leads to the release of endotoxins that promote inflammation in the body. The gut-skin connection is fascinating and I plan to dive more into this in another blog post.
• Aim for 7-9 hours of sleep every night. Both sleep deprivation and poor sleep quality have been shown to interfere with optimal skin barrier function. Also, our skin has its own circadian rhythm. During the day the focus is protection, and at night the focus is repair and rejuvenation. This is also a reason why certain actives are best applied at night (e.g., retinol, niacinamide). Our skin is more permeable at night, so skincare products with actives can more easily penetrate the skin.
• Practice daily stress reduction techniques (e.g., gratitude list, breath work, meditation). Psychological stress has been shown to inhibit optimal skin barrier function as well. Plus, with regards to the gut-skin connection, a high-stress lifestyle can also shift the gut microbiota and lead to dysbiosis.

USE TARGETED NUTRIENTS AND HIGH-QUALITY SUPPLEMENTS

• Sometimes dietary sources may not be enough. Fatty acid supplementation, including flaxseed oil, gamma-linoleic acid, and omega-3 fatty acids, has been shown to improve TEWL and reduce inflammation.
• Incorporating a broad-spectrum probiotic can help the skin microbiome via the gut microbiome.

USE GENTLE SKINCARE THAT SUPPORTS SKIN BARRIER FUNCTION

• Skincare products with prebiotics, probiotics, or postbiotics to support the skin microbiome.
  • Cocokind Probiotic acne serum ($18)
  • Earth Harbor Cloudburst Balancing Gel Hydrator ($28)
  • Wabisabi Botanicals The Offering Probiotic Toner ($38)
  • Mother Dirt The Difference Probiotic Acne Kit ($99)
• Skincare products with a low pH (so more on the acidic side). This can include botanical hydrosols and diluted vinegar sprays.
  • Cocokind Rosewater Facial Toner ($17)
  • True Botanicals Renew Nutrient Mist ($24)
  • Orgaid Balancing Toner with niacinamide ($32)
  • Marie Veronique Balancing HypoTonic ($45)
• Skincare products with free fatty acids (omega-3 and omega-6) and ceramides to support the lipid layer and skin permeability.
  • Cocokind Ceramide Barrier Serum ($20)
  • Wabisabi Botanicals Balancing Act Serum ($26)
  • Marie Veronique Barrier Lipid Complex ($95)

There is still so much to explore with the skin barrier and its connection to acne vulgaris. We need bigger studies with humans (instead of animals). However, the current research available is very promising and something that should be considered when treating acne vulgaris.

MEDICAL DISCLAIMER: the information in this blog post is for informational and educational purposes only. The information and education provided is not intended or implied to supplement or replace professional medical treatment, advice, and/or diagnosis.

References

Del Rosso JQ. The role of skin care as an integral component in the management of acne vulgaris: part 1: the importance of cleanser and moisturizer ingredients, design, and product selection. J Clin Aesthet Dermatol. 2013;6(12):19-27.

Dréno B, Dagnelie MA, Khammari A, Corvec S. The Skin Microbiome: A New Actor in Inflammatory Acne. Am J Clin Dermatol. 2020;21(Suppl 1):18-24. doi:10.1007/s40257-020-00531-1

Jung JY, Kwon HH, Hong JS, et al. Effect of dietary supplementation with omega-3 fatty acid and gamma-linolenic acid on acne vulgaris: a randomised, double-blind, controlled trial. Acta Derm Venereol. 2014;94(5):521-525. doi:10.2340/00015555-1802

Pappas A. Epidermal surface lipids. Dermatoendocrinol. 2009;1(2):72-76. doi:10.4161/derm.1.2.7811

Parke MA, Perez-Sanchez A, Zamil DH, Katta R. Diet and Skin Barrier: The Role of Dietary Interventions on Skin Barrier Function. Dermatol Pract Concept. 2021;11(1):e2021132. Published 2021 Jan 29. doi:10.5826/dpc.1101a132

Rosso JD, Zeichner J, Alexis A, Cohen D, Berson D. Understanding the Epidermal Barrier in Healthy and Compromised Skin: Clinically Relevant Information for the Dermatology Practitioner: Proceedings of an Expert Panel Roundtable Meeting. J Clin Aesthet Dermatol. 2016;9(4 Suppl 1):S2-S8.

Thiboutot D, Del Rosso JQ. Acne Vulgaris and the Epidermal Barrier: Is Acne Vulgaris Associated with Inherent Epidermal Abnormalities that Cause Impairment of Barrier Functions? Do Any Topical Acne Therapies Alter the Structural and/or Functional Integrity of the Epidermal Barrier?. J Clin Aesthet Dermatol. 2013;6(2):18-24.