Figure 2.

The gut microbiota protects against organ failure during Streptococcus pneumoniae-induced sepsis. (A–C) Representative lung slides of untreated (left) and microbiota-depleted (right) mice infected with 1×10⁶ colony forming units (CFU) of S. pneumoniae via the intranasal route and euthanised at indicated time points (6, 24 and 48 h) thereafter to assess pulmonary inflammation and total lung histopathology scores (see Materials and methods). H&E staining; original magnification, ×100. (D and E) Liver and spleen histology shown 48 h after infection. H&E staining; original magnification, ×200 for liver, ×100 for spleen. (F) Systemic blood urea nitrogen (BUN), (G) aspartate aminotransferase (AST), (H) alanine aminotransferase (ALT) and (I) lactate dehydrogenase (LDH) levels assessed 48 h after infection in untreated (black) and gut microbiota-depleted (white) mice. Group size is 8 per group; results are shown as means±SEM; n.s. denotes not significant; *p<0.05 and **p<0.01.