Gut Microbiota Influence Host Metabolism and Immune Responses in Atopic Dermatitis: A Next-Generation Sequencing-Based Functional Profiling Study

Leszek Blicharz,1 Iwona Bukowska-Ośko,2 Karol Perlejewski,2 Vicente Navarro-López,3 Joanna Czuwara,1 Anna Waśkiel-Burnat,1 Zbigniew Samochocki,1 Małgorzata Olszewska,1 Lidia Rudnicka,1 Marek Radkowski2 1Department of Dermatology, Medical University of Warsaw, Warsaw, Poland; 2Department of Immunopathology of Infectious and Parasitic Diseases, Medical University of Warsaw, Warsaw, Poland; 3MiBioPath Research Group, Faculty of Medicine, Universidad Católica San Antonio de Murcia, Murcia, 30107, SpainCorrespondence: Leszek Blicharz, Department of Dermatology, Medical University of Warsaw, Nowogrodzka 59, Warsaw, 02-014, Poland, Email lblicharz@gmail.com Joanna Czuwara, Department of Dermatology, Medical University of Warsaw, Nowogrodzka 59, Warsaw, 02-014, Poland, Email jczuwara@gmail.comPurpose: Gut dysbiosis has been linked to immune imbalance in allergic diseases, but the underlying mechanisms remain unclear. We aimed to verify whether gut microbiota composition is associated with cellular, metabolic, and immune pathways in atopic dermatitis.Patients and Methods: Fifty adults with atopic dermatitis and 25 sex- and age-matched healthy controls were enrolled. Gut microbiome composition was assessed using V3–V4 16S rRNA sequencing. Functional pathways were inferred from microbiome data using PICRUSt (Phylogenetic Investigation of Communities by Reconstruction of Unobserved States).Results: Despite only subtle differences in microbiota composition between patients with atopic dermatitis and controls, PICRUSt analysis identified significant differences in 149 functional pathways. Key pathways enriched in atopic dermatitis involved signal transduction mediated by protein kinases, as well as carbohydrate and lipid metabolism. Downregulated pathways included those related to energy metabolism, amino acid and nucleotide metabolism, antigen processing, and innate immune responses. In patients with atopic dermatitis, microbial diversity increased with EASI scores and IgE levels, ...