• “Gut-Lung Axis”: their bacterial communities are correlated, and gut microbiota protect the host during pneumonia (37) • Oxidative stress impairs bacterial structure (37) • Increase of Gram-Negative Enterobacteriaceae recognized by TLR-4, involved in necrotizing enterocolitis and in lung injury (38). The gene discussed is TLR4; the disease is susceptibility to pneumonia measurement.