Proteobacterial DNA in umbilical cord serum has been linked to features of childhood asthma including maternal atopy, early childhood wheezing, and bronchodilator response, according to the results of a study published in the Journal of Allergy and Clinical Immunology.
Researchers obtained circulating-free bacterial DNA (cfbDNA) in umbilical cord blood from mother-child pairs from the longitudinal Project Viva study and evaluated them for the presence of circulating Proteobacteria DNA. Rates of childhood wheezing were compared between children with circulating Proteobacteria DNA present in the umbilical cord blood and children without it.
Of the 27 maternal-child dyads in the cohort, only 4 reported being diagnosed with asthma. As a result, the association between cfbDNA composition, common risk factors for asthma, and asthma-associated physiologies were evaluated. Children of non-atopic mothers had increased Proteobacteria DNA compared with children of atopic mothers (P =.031). Lower exposure to Proteobacteria was associated with an increased risk for wheezing in these children in both univariate (hazard ratio 3.60; 95% CI, 1.70-7.64; P =.001) and multivariate models, independent of maternal atopic status (adjusted hazard ratio 2.80; 95% CI, 1.46-5.36; P =.002).
The researchers wrote, “In this study, we identified associations between Proteobacteria DNA in cord blood, maternal atopy (a strong risk factor for asthma), and common features of asthma.”
“These findings support the hypothesis that early bacterial exposure patterns [in] immune development which may drive later pulmonary disease,” they concluded.
Turturice B, Gold D, Litonjua A, et al. Lower perinatal exposure to proteobacteria is an independent predictor of early childhood wheezing [published September 8, 2018]. J Allergy Clin Immun. doi:10.1016/j.jaci.2018.06.051