Early-Life Determinants of Atopic Dermatitis: A Comprehensive Multi-Omic Investigation of Microbial, Barrier, and Immune Mechanisms in a prospective birth Cohort

• Applicants: Dr. Yacine Amar; Professor Dr. Tilo Biedermann
• Subject Area: Dermatology
• Term: since 2026
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 580001886

Atopic dermatitis (AD) is a chronic inflammatory skin disorder affecting up to 20% of children and 5% of adults in industrialized countries. A defective skin barrier and a Th2-biased immune response are hallmarks of this disease. Also, a dysbiotic skin microbiome, largely documented by dominant colonization with Staphylococcus aureus, is a key feature. AD is frequently observed in early infancy, but while its pathogenesis is becoming clearer, the early-life factors triggering and driving AD development remain largely unknown. In this prospective birth cohort known as the Munich Atopy Prediction Study (MAPS), we aim to define the infant skin and gut microbiomes in the first four years of life and to elucidate their roles in AD initiation and development. Additionally, maternal microbiomes (from mothers of healthy and AD infants) will be analyzed to identify protective or detrimental taxa transferred to the progeny. Moreover, we will characterise the infant’s nose microbiome, being a potential reservoir of skin colonizers. This study integrates longitudinal, multi-niche (skin, gut, nose, mother), and multi-omic (16S, metagenomics, metabolomics) profiling to unravel the impact of microbes and microbial pathways on AD pathogenesis. By bridging taxonomic shifts to functional metabolic outputs (e.g., SCFA deficits), we also aim to elucidate the mechanisms underlying immune dysregulation in AD. This will allow us to identify microbial and metabolic biomarkers predictive for AD susceptibility, to elucidate maternal contributions to infant AD risk, and to investigate the role of nasal-skin pathogen transmission in AD development. We will also dissect the complex interplay between skin commensal residents (SCRs) and dysbiotic residents (SDRs) in the context of AD, focusing on their influence on early immune dysregulation and skin barrier dysfunction. This research addresses a critical gap in understanding early AD pathogenesis and dysbiosis-driven barrier/immune dysregulations, thereby providing a robust translational framework for the development of early, microbiome-based intervention strategies for AD.

• DFG Programme: Research Grants