Eczema is a common skin condition that impairs children's daily life activities and quality of life. Previous research shows that gut microbiome composition plays an important role in the development of eczema. The present review summarizes evidence on environmental factors related to altered gut microbiota in children with eczema. We searched Medline, PubMed, Embase, and the Cochrane database of Systematic Reviews through October 2015. The search strategy focused on articles published in peer-reviewed, English-language journals with no publication year limit. Only original studies and review articles that reported environmental factors on gut microbiome specific to eczema were included in this review. We selected six studies (total 1990 participants) for full review and identified that the composition of gut microbiota specific to eczema could be influenced by the following environmental factors: length of gestation, mode of delivery, type of feeding, method of treatment, number of older siblings, and other lifestyle factors. There has been inconsistent empirical evidence as to the modulatory effects of gut microbiota on immunological functions in children with eczema. Further research on the environmental-host-microbial interaction is needed to develop a strong base of knowledge for the development and implementation of prevention strategies and policies for eczema.
Keywords: allergy development; childhood eczema; environmental-host-microbial interaction; gene-environment interaction; gut microbiota; immune system; microbiome diversity.