2021

Riskumäki, Matilda; Tessas, Ioannis; Ottman, Noora; Suomalainen, Alina; Werner, Paulina; Karisola, Piia; Lauerma, Antti; Ruokolainen, Lasse; Karkman, Antti; Wisgrill, Lukas; Sinkko, Hanna; Lehtimäki, Jenni; Alenius, Harri; Fyhrquist, Nanna

To the Editor, The prevalence of allergic diseases continues to increase worldwide along with industrialization and urbanization. Emerging evidence provides insights into the connection between the development of chronic inflammatory disorders, such as asthma and allergies, and the human microbiota through the immune-modulatory function of the commensal microbes.1, 2 In addition to the well-established evidence on the role of the gut microbiota in human health and disease, other microbial communities, such as cutaneous microbiota, play an important role in establishing and tuning the host immune system toward a balanced response against commensal and pathogenic microorganisms.3 Additionally, the skin microbiota may promote immune tolerance toward environmental allergens both locally and systemically.4 Interindividual differences and alterations in the skin microbiota composition and its associations with human health and disease are evident, but a greater clarification of the factors that modify the composition of microbiota is needed.1, 2 Factors that have been investigated for their potential interaction with the microbiota include lifestyle, use of medication, and the exposure to a changing environmental biodiversity.1, 5 Here, we explore the composition of skin microbiota in 62 healthy and atopic asymptomatic young adults, and associate that with the characteristics of their childhood and present living environments, allergen-specific serum IgE levels, and the immune function of their peripheral blood mononuclear cells (PBMCs) (see Figure 1A and supplementals for detailed methodological description). We observed distinct associations between the skin microbiota and allergen-specific serum IgE levels and the expression of cytokines, and identified several taxa that may play an important role in augmenting or suppressing the systemic inflammatory immune responses.