Unconjugated bilirubin is associated with protection from early-life wheeze and childhood asthma.

Background: Wheeze and allergic sensitization are the strongest early-life predictors of childhood asthma development; the molecular origins of these early-life phenotypes are poorly understood.

Objectives: We sought to identify metabolites associated with early-life wheeze, allergic sensitization, and childhood asthma.

Methods: We conducted a nested case-control study using Environmental influences on Child Health Outcomes Program cohorts for discovery and independent replication.