Ex vivo Evaluation of Live-MB2 and CX-2 Biotic Strains on Inflammatory and Barrier-Related Biomarkers in a Human Skin Atopic Dermatitis–Like Model

Sejin Cheon,1,* Haeun Lee,1,* Da Yeong Nam,2,* Seokjun Kim,3,4,* Kyeongeun Kim,4 Jaeyu Park,4 Dong-Geol Lee,1 Chun Ho Park,1 So Min Kang,2 Young Mok Heo,1 Hyun Ho Han,5 Dong Keon Yon3,4,6,71Research and Innovation Center, COSMAX BTI, Seongnam, South Korea; 2Korea Biomedical Research Institute (KBI), Seongnam, South Korea; 3Department of Medicine, Kyung Hee University College of Medicine, Seoul, South Korea; 4Center for Digital Health, Medical Science Research Institute, Kyung Hee University Medical Center, Kyung Hee University College of Medicine, Seoul, South Korea; 5Department of Plastic Surgery, Asan Medical Center, Ulsan University College of Medicine, Seoul, South Korea; 6Department of Precision Medicine, College of Medicine, Kyung Hee University, Seoul, South Korea; 7Department of Pediatrics, Kyung Hee University Medical Center, Kyung Hee University College of Medicine, Seoul, South Korea*These authors contributed equally to this workCorrespondence: Dong Keon Yon, Department of Pediatrics, Kyung Hee University Medical Center, Kyung Hee University College of Medicine, Seoul, South Korea, Email [email protected]: Atopic dermatitis (AD) is a chronic inflammatory skin condition characterized by epidermal barrier disruption and immune dysregulation. Live-MB2 and CX-2 were used in an ex vivo human skin AD-like model, which provides a biologically relevant platform for assessing cosmetic ingredients targeting AD-like features.Methods: An AD-like condition was induced in ex vivo human skin explants by repeated tape stripping followed by 2,4-dinitrochlorobenzene stimulation. Skin tissues were treated with Live-MB2 or CX-2 via topical or dermal exposure. Epidermal thickness, IgE, and filaggrin levels were evaluated using hematoxylin and eosin, immunofluorescence, and Enzyme-Linked Immunosorbent Assay analyses.Results: Topical application of Live-MB2 and CX-2 significantly reduced epidermal thickness compared with AD-induced controls. IgE levels were significantly reduced, while filaggrin expression indicated a marked increase, indicating barrier recovery. No treatment-related tissue damage was observed.Conclusion: Live-MB2 and CX-2 showed favorable effects on inflammatory and barrier-related parameters in an ex vivo human skin AD-like model, supporting their potential application as cosmetic ingredients for sensitive and atopic-prone skin.Keywords: Ex vivo human skin, atopic dermatitis, live biotics, skin barrier, filaggrin, cosmetic ingredients