In contrast, disrupting or eliminating this normal commensal microbiota can potentially trigger atypical inflammatory reactions (such as mixed Th1/Th2/Th17–type response with high levels of IL-1β, TNF-α, macrophage inflammatory protein-1β, which may lead to chronic inflammation), which could contribute to the development of bronchopulmonary dysplasia (BPD) [3,6,12]. Here, TNF is linked to bronchopulmonary dysplasia.