# Exploring Microbial and Biophysical Aspects of Dry Skin: In Vivo Test of a Novel Skincare Formulation

## TL;DR

This study tested a new skincare serum to improve dry skin and balance skin bacteria, finding it effective in moisturizing and restoring healthy bacteria.

## Contribution

The study introduces and evaluates a novel skincare formulation combining prebiotics, probiotics, and postbiotics for dry skin.

## Key findings

- The serum improved skin hydration, firmness, elasticity, and reduced roughness.
- The serum increased Cutibacterium acnes and decreased Pseudomonas koreensis, indicating microbiota rebalancing.
- Both serum and placebo helped restore skin microbiota, but only the serum showed targeted bacterial changes.

## Abstract

Dry skin is a prevalent dermatological concern influenced by environmental factors and characterized by compromised skin barrier integrity. In addition to this, skin microbiota is involved and plays a crucial role in maintaining microbial flora balance. This study aims to investigate dry skin condition and microbiota then the efficacy of a novel skincare formulation (Nourish 3‐Biotic Rich Serum) containing prebiotics, probiotics and postbiotics in addressing dry skin symptoms and rebalancing skin microbiota. They are mainly microorganism lysate, together with fermented substances such as oligosaccharides, enzymes, and peptides, that support and provide nourishment to bacteria that live on the skin.

Serum formula and serum placebo were tested in a single‐blind study in which 20 female volunteers aged 28–65 with dry skin were enrolled. Several skin biophysical parameters related to skin barrier condition (stratum corneum water content, transepidermal water loss (TEWL), protein content), mechanical properties (R
0, R
2) and topographic appearance (skin roughness) and skin microbiota analysis were monitored over 30 days of daily application of the products in a split‐face protocol. To better understand the results, the selected panel was then divided into two groups based on different ages: younger (< 50 years) and older (> 50 years).

This study highlighted that the product has proven to have a moisturizing action, exerts a cellular renewal action, improves skin firmness and elasticity, and reduces skin roughness. For microbial analysis, the main evidence is that both the placebo and the product help restore the skin microbiota but only the product increased the quantity of Cutibacterium acnes (one of the primary commensal bacteria of the skin) and was able to decrease the abundance of
Pseudomonas koreensis
usually associated with dry and rosacea skin with beneficial effects.