Urban Exposome and Skin Microbiome in Atopic Dermatitis: A Comparative Study Between Two Brazilian Municipalities
4 affiliations
- 1Department of Dermatology, Escola Paulista de Medicina, Universidade Federal de São Paulo, Botucatu Street, 821, 5th Floor, São Paulo, SP 04023-062 Brazil
- 2Department of Dermatology, Faculdade de Medicina de Botucatu, Universidade Estadual Paulista (UNESP), Botucatu, SP Brazil
- 3Department of Pharmaceutical Sciences, Universidade Federal de São Paulo, Diadema, SP Brazil
- 4International Center of Research (CIPE), A.C.Camargo Cancer Center, São Paulo, SP Brazil
Abstract
Introduction: Atopic dermatitis (AD) is thought to arise from the interplay of skin barrier dysfunction, type 2 immune dysregulation, and cutaneous dysbiosis, the last of these characterized by reduced bacterial diversity and predominance of Staphylococcus aureus. The urban exposome, including air pollution and reduced environmental microbial diversity, may modulate this dysbiosis. We hypothesized that patients with AD residing in a metropolitan area with a higher pollutant burden would show greater skin dysbiosis, reflected by a higher relative abundance of S. aureus, than patients residing in a municipality with a lower pollutant load and greater environmental biodiversity.
Methods: This cross-sectional, comparative study enrolled ten children (6–12 years) and ten adults (20–31 years) with active AD, without specific treatment in the preceding 30 days, residing in the metropolitan region of São Paulo or in Botucatu, an interior municipality of São Paulo State, Brazil. Skin swabs were collected from eczematous lesions and characterized by 16S ribosomal RNA (rRNA) gene (V3–V4) sequencing. Alpha and beta diversity and the relative abundance of S. aureus, S. epidermidis, and S. hominis were compared between municipalities and age groups using generalized linear models, Bray–Curtis dissimilarity, principal coordinates analysis (PCoA), and permutational multivariate analysis of variance (PERMANOVA).
Results: The sample (n = 20) had a predominance of male sex (60%) and moderate AD severity (75%). A total of 658 taxa were identified. Alpha diversity did not differ by municipality or age group, and PERMANOVA revealed no global difference in bacterial community composition (p > 0.1). However, participants residing in the metropolitan municipality showed a significantly higher relative abundance of S. aureus and higher proportions of S. aureus relative to total bacteria and to other staphylococci than those residing in the interior municipality.
Conclusion: Despite similar overall microbial diversity, patients with AD living in a metropolitan municipality showed selective enrichment of S. aureus compared with those in a less polluted interior municipality. These exploratory findings generate the hypothesis that the urban exposome contributes to cutaneous dysbiosis in AD and warrant confirmation in larger studies with objective exposure measurement.
Supplementary Information: The online version contains supplementary material available at https://doi.org/10.1007/s13555-026-01927-3.
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BibTeX
@article{freixo2026urban,
title = {{Urban Exposome and Skin Microbiome in Atopic Dermatitis: A Comparative Study Between Two Brazilian Municipalities}},
author = {Heloísa Silva de Avó Freixo and Hélio Amante Miot and Marília Marufuji Ogawa and Ivanka Miranda de Castro Martins and Vânia Rodrigues Leite e Silva and Newton Andreo Filho and Patrícia Santos Lopes and Romualdo Morandi Filho and Ediléia Bagatin},
journal = {Dermatology and Therapy},
year = {2026},
month = sep,
doi = {10.1007/s13555-026-01927-3},
url = {https://doi.org/10.1007/s13555-026-01927-3},
note = {CC BY-NC 4.0},
}
RIS
TY - JOUR
TI - Urban Exposome and Skin Microbiome in Atopic Dermatitis: A Comparative Study Between Two Brazilian Municipalities
AU - Heloísa Silva de Avó Freixo
AU - Hélio Amante Miot
AU - Marília Marufuji Ogawa
AU - Ivanka Miranda de Castro Martins
AU - Vânia Rodrigues Leite e Silva
AU - Newton Andreo Filho
AU - Patrícia Santos Lopes
AU - Romualdo Morandi Filho
AU - Ediléia Bagatin
PY - 2026
DA - 2026/09/01
JO - Dermatology and Therapy
DO - 10.1007/s13555-026-01927-3
UR - https://doi.org/10.1007/s13555-026-01927-3
AB - Introduction: Atopic dermatitis (AD) is thought to arise from the interplay of skin barrier dysfunction, type 2 immune dysregulation, and cutaneous dysbiosis, the last of these characterized by reduced bacterial diversity and predominance of Staphylococcus aureus. The urban exposome, including air pollution and reduced environmental microbial diversity, may modulate this dysbiosis. We hypothesized that patients with AD residing in a metropolitan area with a higher pollutant burden would show greater skin dysbiosis, reflected by a higher relative abundance of S. aureus, than patients residing in a municipality with a lower pollutant load and greater environmental biodiversity. Methods: This cross-sectional, comparative study enrolled ten children (6–12 years) and ten adults (20–31 years) with active AD, without specific treatment in the preceding 30 days, residing in the metropolitan region of São Paulo or in Botucatu, an interior municipality of São Paulo State, Brazil. Skin swabs were collected from eczematous lesions and characterized by 16S ribosomal RNA (rRNA) gene (V3–V4) sequencing. Alpha and beta diversity and the relative abundance of S. aureus, S. epidermidis, and S. hominis were compared between municipalities and age groups using generalized linear models, Bray–Curtis dissimilarity, principal coordinates analysis (PCoA), and permutational multivariate analysis of variance (PERMANOVA). Results: The sample (n = 20) had a predominance of male sex (60%) and moderate AD severity (75%). A total of 658 taxa were identified. Alpha diversity did not differ by municipality or age group, and PERMANOVA revealed no global difference in bacterial community composition (p > 0.1). However, participants residing in the metropolitan municipality showed a significantly higher relative abundance of S. aureus and higher proportions of S. aureus relative to total bacteria and to other staphylococci than those residing in the interior municipality. Conclusion: Despite similar overall microbial diversity, patients with AD living in a metropolitan municipality showed selective enrichment of S. aureus compared with those in a less polluted interior municipality. These exploratory findings generate the hypothesis that the urban exposome contributes to cutaneous dysbiosis in AD and warrant confirmation in larger studies with objective exposure measurement. Supplementary Information: The online version contains supplementary material available at https://doi.org/10.1007/s13555-026-01927-3.
SN - 2193-8210
SN - 2190-9172
ER -