In line with our previous studies evaluating the effect of beneficial microbes on the susceptibility to viral infections (Villena et al., 2012; Chiba et al., 2013; Tomosada et al., 2013), we found here that the respiratory commensal bacteria C. pseudodiphtheriticum improves resistance to RSV infection through the modulation of IFN-β, IFN-γ, and IL-10. Here, IFNG is linked to viral infectious disease.