Fermented ingredients and eczema

Fermented ingredients are becoming increasingly popular in Korean skincare due to their hydrating, soothing, and skin-strengthening properties. During the fermentation process, ingredients are processed by microorganisms such as bacteria and yeasts. In this process, larger molecules are broken down, giving rise to bioactive substances such as amino acids, peptides, antioxidants, and polysaccharides.

These substances can support the skin in various ways, for instance by improving hydration and strengthening the skin barrier. A review by Lolou and Panayiotidis (2019) describes how fermentation products may influence barrier function, inflammatory responses, and the skin microbiome. However, the exact mechanism varies per ferment, and not every fermented ingredient delivers the same effect.

For people with dry or eczema-prone skin, these properties are particularly interesting. In atopic eczema, the skin barrier is often compromised, causing the skin to lose moisture more quickly and making it more susceptible to irritants and allergens.

Atopic eczema, the skin barrier, and the skin microbiome

Atopic eczema is a chronic skin condition involving multiple factors, including a weakened skin barrier, an overactive immune system, and alterations in the skin microbiome.

Normally, the skin barrier acts as a protective shield that locks in moisture and keeps harmful substances out. In eczema, this barrier functions less effectively, leaving the skin drier and more sensitive.
The skin microbiome also plays a crucial role. It consists of billions of microorganisms that help protect and support the skin. In atopic eczema, this balance is often disrupted: bacterial diversity decreases, and certain bacteria, such as Staphylococcus aureus, can proliferate.

Staphylococcus aureus is commonly found on many people’s skin without causing any issues. However, in individuals with atopic eczema, this bacterium is frequently present in higher amounts, particularly during active flare-ups. An overgrowth can amplify inflammatory responses and further damage the skin barrier.
This creates a vicious cycle: a damaged skin barrier makes the skin more vulnerable to bacterial disruption, while a disrupted microbiome can further weaken the skin.

These insights have sparked increased research into microbiome-focused skincare, aimed at supporting the skin’s natural balance.

Lactobacillus Ferment and Bifida Ferment Lysate

Within Korean skincare, Lactobacillus Ferment and Bifida Ferment Lysate are two well-known fermented ingredients. Both belong to the category of postbiotics: bioactive compounds generated during fermentation. Unlike probiotics, postbiotics do not contain live bacteria.

Lactobacillus Ferment

Lactobacillus is a group of lactic acid bacteria naturally present on and in the human body. In skincare, live bacteria are not used; instead, the beneficial substances produced during fermentation are harvested.
Lactobacillus Ferment is primarily used for its potential to support the skin barrier. Research suggests that certain Lactobacillus ferments can help improve hydration levels and reduce transepidermal water loss.

Additionally, researchers are investigating whether Lactobacillus ferments influence inflammatory processes and the skin microbiome. This makes it an intriguing ingredient for atopic eczema, which is often characterized by a disrupted skin balance and an increase in Staphylococcus aureus.

While Lactobacillus Ferment does not appear to directly eradicate S. aureus, it may help foster a skin environment that better maintains its natural equilibrium.

Bifida Ferment Lysate

Bifida Ferment Lysate is derived from fermented cultures of Bifidobacterium. This process yields substances like amino acids, peptides, and polysaccharides that nourish and support the skin.

A study by Guéniche et al. (2010) examined Bifidobacterium longum lysate in individuals with reactive skin. Researchers observed improvements in skin sensitivity, dryness, and overall resistance to external stimuli.

These findings are particularly compelling for eczema-prone skin, as a weakened barrier and heightened sensitivity are signature traits of atopic eczema. Bifida Ferment Lysate does not appear to exhibit direct antibacterial activity against Staphylococcus aureus; its potential benefits lie predominantly in reinforcing the skin barrier—a healthy barrier being a critical defense against unwanted bacterial disruption.

What does scientific research say?

An increasing body of research focuses on the complex relationship between the skin microbiome, the skin barrier, and atopic eczema. Scientists are looking beyond inflammation alone to understand how the barrier and microorganisms continuously interact.

A systematic review and meta-analysis by Flint et al. (2024) evaluated the effect of topical probiotics on atopic dermatitis. The researchers found that microbiome-focused treatments across various studies helped reduce eczema severity. However, results varied depending on the bacterial strain and product formulation, highlighting the need for further research.

A review by Nowicka et al. (2025) similarly detailed the potential role of microbiome-targeted ingredients in skin disorders associated with dysbiosis. According to the researchers, these ingredients may help strengthen the skin barrier, regulate inflammatory responses, and support healthy interactions between the skin and its native microorganisms.

While current studies are promising, findings from research on specific probiotics or ferments cannot automatically be generalized to all commercial skincare products.

Conclusion

Fermented ingredients such as Lactobacillus Ferment and Bifida Ferment Lysate hold significant promise for dry, sensitive, or eczema-prone skin.

They can potentially contribute to a stronger skin barrier, improved hydration, and a healthier skin environment. In particular, the link between the skin microbiome, the skin barrier, and Staphylococcus aureus continues to be a key focus of modern dermatological research.

However, ferments and postbiotics are not a cure or treatment for eczema. They should primarily be viewed as a supportive addition to a well-rounded skincare routine. For active or severe eczema, medical treatment remains essential.

Scientific References

Lolou V., Panayiotidis M.I. (2019). Functional Role of Probiotics and Prebiotics on Skin Health and Disease. Fermentation, 5(2), 41.
Guéniche A. et al. (2010). Bifidobacterium longum lysate, a new ingredient for reactive skin. Experimental Dermatology.
Flint E. et al. (2024). Topical Probiotics Reduce Atopic Dermatitis Severity: A Systematic Review and Meta-Analysis of Double-Blind, Randomized, Placebo-Controlled Trials.
Nowicka D. et al. (2025). Topical Probiotics as a Novel Approach in the Treatment of Chronic Dermatoses Associated with Skin Dysbiosis: A Narrative Review. International Journal of Molecular Sciences, 26(20), 10195.