Skin microbiome before development of atopic dermatitis: Early colonization with commensal staphylococci at 2 months is associated with a lower risk of atopic dermatitis at 1 year.
Disease flares of established atopic dermatitis (AD) are generally associated with a low-diversity skin microbiota and Staphylococcus aureus dominance. The temporal transition of the skin microbiome between early infancy and the dysbiosis of established AD is unknown.



We randomly selected 50 children from the Cork Babies After SCOPE: Evaluating the Longitudinal Impact Using Neurological and Nutritional Endpoints (BASELINE) longitudinal birth cohort for microbiome sampling at 3 points in the first 6 months of life at 4 skin sites relevant to AD: the antecubital and popliteal fossae, nasal tip, and cheek. We identified 10 infants with AD and compared them with 10 randomly selected control infants with no AD. We performed bacterial 16S ribosomal RNA sequencing and analysis directly from clinical samples.



Bacterial community structures and diversity shifted over time, suggesting that age strongly affects the skin microbiome in infants. Unlike established AD, these patients with infantile AD did not have noticeably dysbiotic communities before or with disease and were not colonized by S aureus. In comparing patients and control subjects, infants who had affected skin at month 12 had statistically significant differences in bacterial communities on the antecubital fossa at month 2 compared with infants who were unaffected at month 12. In particular, commensal staphylococci were significantly less abundant in infants affected at month 12, suggesting that this genus might protect against the later development of AD.



This study suggests that 12-month-old infants with AD were not colonized with S aureus before having AD. Additional studies are needed to confirm whether colonization with commensal staphylococci modulates skin immunity and attenuates development of AD.
Dermatology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Md.
Elizabeth A
EA
Kennedy
Paediatrics and Child Health, University College, Cork, and the Irish Centre for Fetal and Neonatal Translational (INFANT) Research, Cork University Maternity Hospital, Cork, Ireland.
Jennifer
J
Connolly
Paediatrics and Child Health, University College, Cork, and the Irish Centre for Fetal and Neonatal Translational (INFANT) Research, Cork University Maternity Hospital, Cork, Ireland.
Jonathan O'B
JO
Hourihane
Clinical Medicine, Trinity College Dublin, Dublin, Ireland; National Children's Research Centre, Our Lady's Children's Hospital Crumlin, Dublin, Ireland.
Padraic G
PG
Fallon
Dermatology and Genetic Medicine, University of Dundee, Dundee, United Kingdom.
W H Irwin
WHI
McLean
Paediatrics and Child Health, University College, Cork, and the Irish Centre for Fetal and Neonatal Translational (INFANT) Research, Cork University Maternity Hospital, Cork, Ireland.
Deirdre
D
Murray
Dermatology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Md.
Jay-Hyun
JH
Jo
Translational and Functional Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Md.
Julia A
JA
Segre
Dermatology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Md. Electronic address: konghe@mail.nih.gov.
Heidi H
HH
Kong
Clinical Medicine, Trinity College Dublin, Dublin, Ireland; National Children's Research Centre, Our Lady's Children's Hospital Crumlin, Dublin, Ireland; Paediatric Dermatology, Our Lady's Children's Hospital Crumlin, Dublin, Ireland. Electronic address: irvinea@tcd.ie.
Alan D
AD
Irvine
D001419:Bacteria / Q000235:genetics; D002675:Child, Preschool; D003876:Dermatitis, Atopic / Q000382:microbiology*; D005260:Female; D000091344:Filaggrin Proteins; D006801:Humans; D007223:Infant; D007381:Intermediate Filament Proteins / Q000235:genetics; D008297:Male; D064307:Microbiota; D012329:RNA, Bacterial / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012307:Risk Factors; D012867:Skin / Q000382:microbiology*
D000091344:Filaggrin Proteins; D007381:Intermediate Filament Proteins; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S
16S sequencing; Staphylococcus aureus; atopic dermatitis; longitudinal birth cohort; microbiome; skin