The lung microbiota of post-sepsis mice was significantly enriched with numerous bacteria commonly found in the murine gut, including members of the Bacteroidales order, Enterococcus species, and Lachnospiraceae species. A member of the Bacteroidales order (OTU008) was identified as a key microbial driver of the altered lung communities. Alveolar TNF-α was positively correlated with the relative abundance of Proteobacteria. The gene discussed is TNF; the disease is Sepsis.