50812 Infant Skin Microbiome is Associated with Decreased Risk of Atopic Dermatitis and Affected by Early Use of an Emollient

The STOP AD trial, a randomized, open-label trial evaluating the effect of short-term (first 4 postnatal days to 8 weeks) skin barrier protection using a colloidal oat and glycerin containing balm in infants with a parent with allergic disease, demonstrated decreased cumulative incidence and prevalence of AD at 6 and 12 months of age [1]. Skin swabs were collected from the cheek and antecubital fossa of the elbow at baseline, 8 weeks, and 12 months from a subset of subjects from each of the intervention arm (43 of 119) and control arm (43 of 138) and the skin microbiome taxonomically and functionally profiled based on shotgun sequencing. Abundance of multiple taxa by 8 weeks was associated with a lower risk of development of AD, most prominently with development at the 6-month time point. Some of the more abundant taxa were shared between the elbow and cheek. The emollient intervention group had increased abundance of several taxa associated with a lower risk of AD compared to the control group. In subjects with a filaggrin loss-of-function (LOF) mutation, functional analysis identified several differences associated with the development of AD, including increased methane metabolism, which has previously been associated with AD. Such associations were not observed for filaggrin wild type subjects. Abundance of skin microbiome taxa by 8 weeks of age was associated with decreased risk of the development of AD. Short term emollient use from birth to 8 weeks promoted their abundance.