Sensitive skin and low mineralized thermal spring water: Biomechanical and microbiota benefits

Summary: Abstract Body: Introduction: The benefits of low mineral content thermal spring water (LM-TSW) on skin diseases have been known for centuries, including effects on cell membrane fluidity, keratinocyte differentiation, antioxidative, anti-inflammatory properties. However, its effects on sensitive skin are not yet studied. Sensitive skin is characterized by sensations like tightness, pruritus, or tingling. Objectives: This study aimed to access the efficacity of LM-TSW on sensitive skin by biomechanical and microbiota analysis. Materials & Methods: A crossover clinical study involved 24 subjects with sensitive skin, randomized into two groups: each group receiving 6 sprays daily of LM-TSW or MR-TSW, on the face for 8 days. Analyses were performed at day 0 and day 8, including clinical scores, biometrological tests, skin biomechanics (atomic force microscopy), intercorneocyte cohesion imaging, microbiota analysis, and user perceptions. Results: After 8 days, LM-TSW improved sensitive skin parameters: cutaneous irritability, redness, tightness, discomfort, and heat sensation. Skin microrelief showed a significant reduction in roughness, indicating a smoothing effect. LM-TSW also improved skin elasticity at the surface and depth of the stratum corneum, and at the cellular level. This biomechanical effect was associated with better corneocyte cohesion, enhancing the skin barrier. LM-TSW was also improved bacterial richness. LM-TSW was improved user perceptions, with subjects reporting significantly softer, more comfortable skin compared to the MR-TSW group. Conclusion: This study demonstrates, for the first time, the clinical efficacy of LM-TSW on sensitive skin by regulating skin biomechanics and bacterial richness, leading to significant improvements in cutaneous symptoms for sensitive skin volunteers. Céline Mias¹, Jennifer Theunis², Julie Noharet¹, Sophie Baradat², Camille Satgé¹, Delphine Bes Vuillermoz¹, Audrey Houcine¹, Julien Chlasta³, Aline Stennevin⁴, Gautier Doat⁴, Sandrine Bessou-Touya¹, Hélène Duplan¹ 1. R&D Department, Pierre Fabre Dermo-Cosmetique SAS, Toulouse, Occitanie, France. 2. R&D Department, Pierre Fabre Dermo-Cosmetique SAS, Toulouse, Occitanie, France. 3. Biomeca, Lyon, France. 4. Medical Department, Laboratoires dermatologiques Avène SAS, Toulouse, Occitanie, France. Clinical Research: Interventional Research