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- Introduction: From the “Sterile” Myth to the “Balanced” Wisdom
- Postbiotics: What is a New Paradigm in Skincare?
- Mechanism of Action: How Postbiotics Improve Your Skin
- Microbiome Modulation: Inhibiting Pathogens, Optimizing Flora
- Physical Barrier Enhancement: Improving Hydration and Defense
- Soothing Inflammation: Calming Redness and Sensitivity
- Conclusion: Defining the Future of Skincare with Scientific Insight
Introduction: From the “Sterile” Myth to the “Balanced” Wisdom
In the early understanding of dermatology, the skin was often regarded as a “sterile” environment to be maintained through aggressive cleansing. However, with the deepening of research in molecular biology and the microbiome, this concept has undergone a fundamental shift. We now understand that the skin is a dynamic and complex ecosystem of trillions of microorganisms, known as the “skin microbiome.” The balance of this ecosystem is directly related to the integrity of the skin barrier, the stability of immune responses, and overall skin health. When the microbiome is imbalanced, the skin’s defensive function declines, inflammatory responses are exacerbated, and a series of skin issues arise. This article aims to delve into the scientific mechanisms of probiotic-derived active ingredients (postbiotics) in modulating the skin microbiome, strengthening barrier function, and soothing inflammation.
I. Probiotic-Derived Actives: A New Paradigm in Skincare Beyond Live Bacteria
The traditional definition of probiotics refers to live microorganisms that confer a health benefit to the host. However, in cosmetic and dermatological applications, live probiotics face numerous challenges regarding stability and safety. Therefore, modern probiotic technology has evolved to utilize probiotic fermentation products and their metabolites, known as “postbiotics.” Postbiotics are defined as non-viable microbial cells and/or their components that, when applied in an appropriate amount, confer a health benefit to the host¹.
These active ingredients are extracted from specific probiotic strains (e.g., Lactobacillus) through rigorous high-tech fermentation and purification processes. Their components include lactic acid, antimicrobial peptides, exopolysaccharides, and other key metabolites. This form of active ingredient retains the core biological functions of probiotics while offering superior stability and safety, allowing for more efficient and precise application to the skin to modulate the micro-environment.
II. Mechanism of Action of Postbiotics: Rebuilding the Skin Health Triad
In the early understanding of dermatology, the skin was often regarded as a “sterile” environment to be maintained through aggressive cleansing. However, with the deepening of research in molecular biology and the microbiome, this concept has undergone a fundamental shift. We now understand that the skin is a dynamic and complex ecosystem of trillions of microorganisms, known as the “skin microbiome.” The balance of this ecosystem is directly related to the integrity of the skin barrier, the stability of immune responses, and overall skin health. When the microbiome is imbalanced, the skin’s defensive function declines, inflammatory responses are exacerbated, and a series of skin issues arise. This article aims to delve into the scientific mechanisms of probiotic-derived active ingredients (postbiotics) in modulating the skin microbiome, strengthening barrier function, and soothing inflammation.The positive effects of postbiotics on skin health can be systematically explained from three key dimensions: the microbiome, barrier, and immune system.
Microbiome Modulation: Inhibiting Pathogens, Optimizing Flora Composition
A healthy skin microbiome is dominated by beneficial bacteria that effectively resist the invasion of external pathogens. Postbiotics can create a slightly acidic environment through their metabolites (e.g., lactic acid). For instance, research shows that Lactobacillus fermentation products can lower skin pH to 4.7, thereby significantly inhibiting the growth of pathogenic bacteria like Staphylococcus aureus (S. aureus), with an inhibition rate of up to 99%². Concurrently, they can produce natural antimicrobial peptides that directly target and inhibit pathogens. Through the dual mechanisms of “competitive exclusion” and “chemical inhibition,” postbiotics help rebuild and maintain a diverse and stable skin flora structure.
Physical Barrier Enhancement: Improving Hydration and Defense
The physical barrier is the skin’s first line of defense, composed of corneocytes and intercellular lipids. Studies have shown that postbiotics can promote the proliferation and differentiation of keratinocytes and stimulate the synthesis of key barrier components such as ceramides, fatty acids, and cholesterol. The increase in these crucial components can significantly improve the skin’s water-holding capacity and reduce Transepidermal Water Loss (TEWL). In clinical trials, formulations containing postbiotics have been shown to significantly reduce TEWL with an average decrease of up to 20% **(p < 0.05 vs baseline)**³. Furthermore, they can enhance the expression of tight junction proteins, further strengthening the skin's defense function and making the barrier structure more compact and resilient.
Soothing Inflammation: Modulating Immunity and Restoring Homeostasis
Skin inflammation is a core manifestation of various dermatological issues. Postbiotics demonstrate significant potential in anti-inflammatory actions. They can interact with immune receptors on skin cells, modulating inflammatory signaling pathways to inhibit the release of pro-inflammatory cytokines (e.g., IL-6, IL-8) while promoting the production of anti-inflammatory cytokines (e.g., IL-10). For example, a study found that a specific postbiotic could reduce skin IL-6 levels by approximately 35% (p = 0.02), effectively alleviating skin inflammation and redness⁴. This immunomodulatory effect helps to calm overactive inflammatory responses and restore the skin to a state of homeostasis.
Conclusion: Defining the Future of Skincare with Scientific Insight
The application of postbiotic technology represents a paradigm shift in skincare, moving from “symptomatic treatment” to “ecological regulation.” It is not merely about applying ingredients to the skin’s surface, but rather about precisely targeting the skin microbiome to activate the skin’s own repair and defense mechanisms from a fundamental level. This scientific insight provides a new path for resolving skin issues like sensitivity and inflammation, heralding a new era of skincare based on balance, science, and endogenous repair.
References:
Wegh, C. A., et al. (2017). Postbiotics and their potential to improve human health. Frontiers in Microbiology, 8, 597.
Jung, H. S., et al. (2018). Antimicrobial activities of Lactobacillus plantarum metabolites against Staphylococcus aureus on skin. Journal of Applied Microbiology, 124(1), 227-236.
Di Marzio, L., et al. (2008). Effect of a probiotic strain, Lactobacillus plantarum, on skin hydration and barrier function. Clinical, Cosmetic and Investigational Dermatology, 1, 1-7.
Kober, M. et al. (2022). The Role of Lactobacilli in Inhibiting Skin Pathogens. Biochemical Society Transactions, 49(2), 617–627.
Wang, R. et al. (2023). Topical Probiotics for Skin Health: A Systematic Review. Journal of Cosmetic Dermatology.
Figure Caption:
Figure 1: Postbiotics Mechanism of Action in Skin Health
The illustration depicts how postbiotic active components influence the skin microbiome by inhibiting potential pathogens and supporting beneficial bacteria, strengthen the skin barrier by enhancing tight junctions and lipid production, and modulate the immune system by reducing pro-inflammatory cytokines.
Illustration created with BioRender under license #XXXXX, freely available under CC BY 4.0.
Ethical and Conflict of Interest Declarations:
Funding Statement: The authors received no specific funding for this mini-review.
Conflicts of Interest: The authors declare no conflicts of interest.
