Skin-Brain Axis: Opportunities to Rethinking The Microbiome & Exposome in Neurocosmetics by OxiProteomics

Neurocosmetics marks a shift in the beauty industry’s approach, acknowledging the profound inter–relationship between our skin and other organ systems, in this case the central nervous system and more specifically, our brain. By delving into the intricate relationship between our skin and brain, cosmetics brands are revolutionizing the way we perceive and experience beauty products.

Brands recognize that our skin, being the largest organ and an interface to the external world, holds the power to influence our mood, confidence, and overall sense of self. Importantly, our skin is a sensory organ that reacts and captures environmental stimuli including thermal, mechanical, chemical, nociceptive and microbiome ones. Emotional stress is also important in the development of atopic flares confirming the key role of the brain on the skin’s over–reactivity to environmental stimuli including microbiome or exposome.

The field of neurocosmetics has identified two fundamental concepts to investigate the intricate relationship between the skin and the brain. The first concept revolves around the capture and interpretation of mechanical stimuli, specifically touch and pressure perception, involving specialized structures localized in the dermis such as Merkel disks (soft touch), Root hair plexus (touch), Meissner’s corpuscle (soft touch), Pacinian corpuscle (pressure) and Ruffini’s ending (pressure). These sensations involve specialized structures located in the dermis, working in tandem to relay sensory information to the brain. The second one and probably the most characterized, is the neuro–immune cutaneous system (NICS). In addition to mechanical stimuli, skin also reacts to thermal stimuli, exposome (pollutants, and UV), inflammatory environment, and the microbial secretome (molecules, including proteins, metabolites, and other bioactive compounds, that are secreted or released by microorganisms living in our skin) that was analyzed by the brain as nociceptive.

Following external stimulation or emotional stress, C–fibers release neuropeptides (SP, CGRP, GRP, VIP, NPY), which act on neighboring cells, this phenomenon is called neurogenic inflammation. All of these mediators drive skin inflammation allowing dendritic cells to mediate Th2 polarization and enhancing local skin inflammation via inflammatory (potential biomarkers: Interleukin–5, IL–4, IL–13) and purinergic (IL–31) cytokines. However, focusing on NICS alone to investigate neuro–cosmetics could be a restrictive vision.

Rethinking skin–brain axis includes the microbiome as one part of NICS. The microbiome plays a key role in skin homeostasis by forming a protective biofilm against opportunistic bacteria and exposome. In addition, bacterial secretions can activate the kallikrein pro–form involved in skin desquamation thus enhancing barrier disruption. The neuropeptides also enhance the virulence of Staphylococcus aureus and S. epidermimis, suggesting that our emotions could directly impact and drive our microbiome toward dysbiosis. S. aureus and S. epidermimiss are two species of bacteria commonly found on human skin, while they are both members of the Staphylococcus genus, they have different effects on skin health (Figure 1).

Figure 1. Schematic representation of the complex.

Ongoing R&D programmes at Oxiproteomics aim to approach this topic with a holistic view, by the development of innovative testing methods to investigate the skin–brain axis using human skin in–vitro and ex–vivo approaches, modulated by neurogenic mediators and the microbiome secretome taking into consideration the exposome (urban pollution, UV and visible irradiation, etc). Our goal is to identify early and specific biomarkers that provide novel targets for the efficacy evaluation of skincare ingredients and finished products.

By aligning skincare with the pursuit of mental wellness, neurocosmetics hold the potential to revolutionize our self–care routines. The integration of neuroscientific principles into cosmetic development represents a profound shift towards a more holistic understanding of beauty and personal care. In conclusion, as the cosmetic industry embraces the concept of neurocosmetics, we can expect a wave of transformative skin care products that not only enhance our appearance but also elevate our mood and well–being. This convergence of science and skincare is poised to shape the future of the Cosmetic industry, unlocking new possibilities for self–care and emotional empowerment.

While research in the Skin–Brain Axis area is still emerging, some skincare product claims have started incorporating the concept of the skin–brain axis to promote their products. Here are a few examples of such claims: Stress reduction, boosts mental health and beauty, sleep support, and Mood enhancement. It is important to note that while these claims may sound promising, scientific research in the field of the skin–brain axis is still developing. It is essential that the efficacy of skin care products and their active ingredients is backed by reliable scientific evidence demonstrating their benefits to improve and maintain skin health. By prioritizing scientific results and transparent claims, cosmetics brands are sharing this information to ensure satisfaction and confidence among consumers. OxiProteomics Scientific team reinforces their commitment to providing high–quality efficacy test solutions that deliver tangible scientific data and images to brands and cosmetics manufacturers.