TLR4 and pneumococcal infection: Similarly, the pulmonary bacterial load of gut microbiota-disrupted wild-type mice (Fig 1B and Table 2) increased by 3.48-fold after 6 hours (P = 0.001) and 6.95-fold after 12 hours (P = 0.016) of pneumococcal infection compared to the undisrupted controls, while that of TLR4-deficient mice (Fig 5B and Table 2) increased by only 0.42-fold (P = 0.167) and 0.05-fold (P = 0.879) at the respective time points.