Farm Exposure Influences Skin Microbiota In Infancy
Saturday, March 3, 2018: 3:00 PM
S320CD (Convention Center)
Cheryl A. Steiman, MD, , , , , , , , ,
RATIONALE: Wisconsin dairy farm children are less likely to develop atopic dermatitis (AD) compared to non-farm. We hypothesize that there is a more diverse skin microbiota in farm-raised infants compared to non-farm and a less diverse skin microbiota in subjects who develop AD.

METHODS: Parents reported by questionnaire if a healthcare provider diagnosed the child with AD at clinic visits (2, 9, 12, 18, 24 months) and phone calls (6, 15, 21 months). We sampled the antecubital fossa of 2-month-old subjects (n=187) and profiled the microbiota by sequencing the V4 region of the 16S rRNA gene. We used alpha diversity (Faith’s phylogenetic diversity) and beta diversity (unweighted UniFrac) to analyze effects of farm-status. We used alpha diversity (Shannon diversity), beta diversity (weighted UniFrac) and taxon relative abundance comparisons (zero-inflated negative binomial regression) to analyze effects of AD-status.

RESULTS: AD was significantly less prevalent in the farm group; this relationship was age dependent with strong differences in the second year of life (p=0.004). The farm group had significantly higher skin microbial diversity (p=0.013) and distinct community compositions (p<0.001, R­2=0.020). AD was associated with distinct bacterial communities (p=0.039, R­2=0.015), with a trend (p=0.086) towards lower diversity. AD was significantly depleted for a Corynebacterium taxon (q=0.047).

CONCLUSIONS: Wisconsin dairy farm-raised infants have a more diverse skin microbiota compared to non-farm. A less diverse microbiota and early-life depletion of Corynebacterium are risk factors for developing AD. These findings suggest that the 2-month skin microbiota of farm-raised children may contribute to the reduced incidence of AD later in life.