Yu Ri Woo and Hei Sung Kim*

Department of Dermatology, Incheon St. Mary’s Hospital, College of Medicine, The Catholic University of

Korea, Seoul, Republic of Korea

EDITED BY

Alexandra P. Marques,

University of Minho, Portugal

REVIEWED BY

Piotr Konopelski,

Medical University of Warsaw, Poland

Karolina Chilicka-Hebel,

Opole University, Poland

*CORRESPONDENCE

Hei Sung Kim,

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RECEIVED 16 October 2023

ACCEPTED 03 January 2024

PUBLISHED 19 January 2024

CITATION

Woo YR and Kim HS (2024), Interaction between the microbiota and the skin barrier in aging skin: a comprehensive review.

Front. Physiol. 15:1322205.

doi: 10.3389/fphys.2024.1322205

© 2024 Woo and Kim. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY).

The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

The interplay between the microbes and the skin barrier holds pivotal significance in skin health and aging. The skin and gut, both of which are critical immune and neuroendocrine system, harbor microbes that are kept in balance. Microbial shifts are seen with aging and may accelerate age-related skin changes. This comprehensive review investigates the intricate connection between microbe dynamics, skin barrier, and the aging process. The gut microbe plays essential roles in the human body, safeguarding the host, modulating metabolism, and shaping immunity. Aging can perturb the gut microbiome which in turn accentuates inflammaging by further promoting senescent cell accumulation and compromising the host’s immune response. Skin microbiota diligently upholds the epidermal barrier, adeptly fending off pathogens. The aging skin encompasses alterations in the stratum corneum structure and lipid content, which negatively impact the skin’s barrier function with decreased moisture retention and increased vulnerability to infection. Efficacious restoration of the skin barrier and dysbiosis with strategic integration of acidic cleansers, emollients with optimal lipid composition, antioxidants, and judicious photoprotection may be a proactive approach to aging. Furthermore, modulation of the gut-skin axis through probiotics, prebiotics, and postbiotics emerges as a promising avenue to enhance skin health as studies have substantiated their efficacy in enhancing hydration, reducing wrinkles, and fortifying barrier integrity. In summary, the intricate interplay between microbes and skin barrier function is intrinsically woven into the tapestry of aging. Sound understanding of these interactions, coupled with strategic interventions aimed at recalibrating the microbiota and barrier equilibrium, holds the potential to ameliorate skin aging. Further in-depth studies are necessary to better understand skin-aging and develop targeted strategies for successful aging.

KEYWORDS

aging, skin, microbe, skin barrier, gut

Fan Yang1 Xinyuan Zhang2 Hua Wang1 Miao Guo1 Jinlong Zhang1 Xuejiao Feng3 Jiayi Yu3 Jiahui Yang3 Jinjin Zhu4 Yiyu Wang3

1 Research & Development Center, Mageline Biology Tech Co., Ltd, Wuhan, Hubei, China

2 Shanghai Skinshield Clinical Testing and Technological Research Ltd., Shanghai, China

3 Department of Dermatology, Air Force Medical Center, PLA, Beijing, China

4 Department of Dermatology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology (HUST), Wuhan, China

Correspondence

Jinjin Zhu, Department of Dermatology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology (HUST), Wuhan, 430022, China.

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Yiyu Wang, Department of Dermatology, Air Force Medical Center, PLA, Beijing, China.

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Abstract

Background: The delicate periorbital region is susceptible to skin dehydration, wrinkles, and loss of elasticity. Thus, targeted and effective anti-aging interventions are necessary for the periorbital area.

Aim: To evaluate the efficacy and safety of a new anti-aging eye cream formulated with the active complex (Yeast/rice fermentation filtrate, N-acetylneuraminic acid, palmityl tripeptide-1, and palmitoyl tetrapeptide-7).

Methods: The cell viability and expressions of key extracellular matrix (ECM) components of the active complex were evaluated using a human skin fibroblast model. In the 12-week clinical trial, skin hydration, elasticity, facial photographs, and collagen density following eye cream application were assessed using Corneometer, Cutometer, VISIA, and ultrasound device, respectively. Dermatologists and participants evaluated clinical efficacy and safety at baseline, and after 4, 8, and 12 weeks.

Results: PCR and immunofluorescent analyses revealed that the active complex significantly stimulated fibroblast proliferation (p < 0.05) and markedly promote the synthesis of collagen and elastin. Clinical findings exhibited a substantial enhancement in skin hydration (28.12%), elasticity (18.81%), and collagen production (54.99%) following 12 weeks of eye cream application. Dermatological evaluations and participants’ assessments reported a significant improvement in skin moisture, roughness, elasticity, as well as fine lines and wrinkles by week 8.

Conclusion: The new anti-aging eye cream, enriched with the active complex, demonstrates comprehensive rejuvenating effects, effectively addressing aging concerns in the periorbital area, coupled with a high safety profile.

KEYWORDS

anti-aging, collagen, elastin, extracellular matrix, eye cream, wrinkle

Eung Ho Choi , Hyun Kang

Department of Dermatology, Yonsei University Wonju College of Medicine, Wonju, Korea

ABSTRACT

Skin barrier function relies on three essential components: stratum corneum (SC) lipids, natural moisturizing factors (NMFs), and the acidic pH of the SC surface. Three endogenous pathways contribute to acidity: free fatty acids from phospholipids, trans-urocanic acid from filaggrin (FLG), and the sodium-proton antiporter (NHE1) activity. An acidic SC environment boosts the activity of enzymes to produce ceramides, which are vital for skin health. Conversely, an elevated pH can lead to increased skin infections, reduced lipid-processing enzyme activity, impaired permeability barrier recovery, and compromised integrity and cohesion of the SC due to increased serine protease (SP) activity. Elevated SC pH is observed in neonatal, aged, and inflamed skin. In atopic dermatitis (AD), it results from decreased NMF due to reduced FLG degradation, decreased fatty acids from reduced lamellar body secretion, and reduced lactic acid due to decreased sweating. Moreover, the imbalance between SP and SP inhibitors disrupts barrier homeostasis. However, acidifying the SC can help restore balance and reduce SP activity. Acidic water bathing has been found to be safe and effective for AD. In three different AD murine models, SC acidification prevented the progression of AD to respiratory allergies. In aging skin, a decrease in NHE1 leads to an increased skin pH. Mild acidic skin care products or moisturizers containing NHE1 activators can normalize skin pH and improve barrier function. In conclusion, maintaining the acidity of the SC is crucial for healthy skin barrier function, leading to significant benefits for various skin conditions, such as AD and aging-related skin issues.

Keywords: Skin aging; Atopic dermatitis; Sodium-proton antiporter; Staratum corneum; Epidermal barrier 

Rita Rezzani 1,2,3,* , Gaia Favero 1,2 , Giorgia Cominelli 1 , Daniela Pinto 2,4 and Fabio Rinaldi 2,4

1 Anatomy and Physiopathology Division, Department of Clinical and Experimental Sciences, University of Brescia, 25123 Brescia, Italy; 该Email地址已收到反垃圾邮件插件保护。要显示它您需要在浏览器中启用JavaScript。 (G.F.); 该Email地址已收到反垃圾邮件插件保护。要显示它您需要在浏览器中启用JavaScript。 (G.C.)

2 Interdipartimental University Center of Research “Adaption and Regeneration of Tissues and Organs (ARTO)”, University of Brescia, 25123 Brescia, Italy; 该Email地址已收到反垃圾邮件插件保护。要显示它您需要在浏览器中启用JavaScript。 (D.P.); 该Email地址已收到反垃圾邮件插件保护。要显示它您需要在浏览器中启用JavaScript。 (F.R.)

3 Italian Society for the Study of Orofacial Pain (Società Italiana Studio Dolore Orofacciale—SISDO), 25123 Brescia, Italy

4 Human Microbiome Advanced Project Institute, 20129 Milan, Italy * Correspondence: 该Email地址已收到反垃圾邮件插件保护。要显示它您需要在浏览器中启用JavaScript。; Tel.: +39-0303717483

Abstract: The skin is considered the most important organ system in mammals, and as the population ages, it is important to consider skin aging and anti-aging therapeutic strategies. Exposure of the skin to various insults induces significant changes throughout our lives, differentiating the skin of a young adult from that of an older adult. These changes are caused by a combination of intrinsic and extrinsic aging. We report the interactions between skin aging and its metabolism, showing that the network is due to several factors. For example, iron is an important nutrient for humans, but its level increases with aging, inducing deleterious effects on cellular functions. Recently, it was discovered that ferroptosis, or iron-dependent cell death, is linked to aging and skin diseases. The pursuit of new molecular targets for ferroptosis has recently attracted attention. Prevention of ferroptosis is an effective therapeutic strategy for the treatment of diseases, especially in old age. However, the pathological and biological mechanisms underlying ferroptosis are still not fully understood, especially in skin diseases such as melanoma and autoimmune diseases. Only a few basic studies on regulated cell death exist, and the challenge is to turn the studies into clinical applications.

Keywords: aging; autoimmune diseases; cutaneous diseases; ferroptosis; gut microbiota; melanoma; skin

Citation: Rezzani, R.; Favero, G.; Cominelli, G.; Pinto, D.; Rinaldi, F. Skin Aging and the Upcoming Role of Ferroptosis in Geroscience. Int. J. Mol. Sci. 2024, 25, 8238. https://doi.org/ 10.3390/ijms25158238

Academic Editor: Michal Zmijewski

Received: 1 July 2024

Revised: 25 July 2024

Accepted: 26 July 2024

Published: 28 July 2024

Copyright: © 2024 by the authors. Licensee MDPI, Basel, Switzerland.

This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).