Link Between Gut Bacteria, Atopic Dermatitis Development
The investigators sought to determine how the natural environment or diet protects potentially at-risk populations from such allergic conditions as atopic dermatitis.
A detailed microbiome analysis conducted in a group of children from rural South African communities has revealed differences in the gut microbiota of toddlers with atopic dermatitis (AD) linked to their diet. Results were published in the Journal of Allergy and Clinical Immunology.
The investigators sought to determine how the natural environment or diet protects potentially at-risk populations from such allergic conditions as AD, thus helping to elucidate the causes of the current global increase in atopic diseases. They characterized the gut microbiota of South african black (Xhosa) children from the remote rural Mqanduli district of the Eastern Cape in association with AD. Patients with AD were recruited from the Dermatology Department of the Nelson Mandela Academic Hospital in Umtata, Eastern Cape, South Africa. Control, nonallergic, non-food-sensitized participants were recruited from areas surrounding 10 district community health clinics.
A total of 83 children were recruited for this study: 36 participants with AD and 47 control patients without AD. The fecal microbiota of these children were analyzed and compared with respect to the presence of AD, other clinical variables, and their diet.
AD was significantly associated with food sensitization (P =.0001), but not with allergic rhinitis (P =.14) or wheezing (P =.73). Moreover, children with AD had a significantly higher daily consumption of total sugar (P =.007) and saturated fat (P =.003) than control patients.
Notably, having been breastfed at all, as well as the duration of exclusive breastfeeding and total breastfeeding, was not associated with an individual's AD status (P =.73, P =.67, and P =.72, respectively).
The relative abundance of Prevotella copri was significantly decreased in children with AD compared with those without the disorder (1.45±3.94 vs 0.38±0.53, respectively; P <.00001). Further, children with high sugar content in their diet had significantly lower P copri levels than those with lower median sugar intake (0.43±0.52 vs 1.04±3.32, respectively; P <.0001).
The investigators concluded that based on the decreased prevalence of P copri in the participants with AD, these bacteria may play a protective role against the development of this disorder. Additional studies are warranted to evaluate the underlying mechanism of this association relative to gut microbiota.
Mahdavinia M, Rasmussen HE, Botha M, et al. Effects of diet on the childhood gut microbiome and its implications for atopic dermatitis [published online December 19, 2018]. J Allergy Clin Immunol. doi: 10.1016/j.jaci.2018.11.034