Klebsiella pneumoniae infection is associated with alterations in the gut microbiome and lung metabolome

Gut microbiota is involved in maintaining homeostasis, and intestinal dysbiosis may lead to opportunistic infections and diseases. Pathogens can disrupt the gut homeostasis and establish colonization, but how they modulate the microbiome and metabolome along the gut-lung axis warrants further investigation. In the present study, we used a classical low virulence Klebsiella pneumoniae (cKp) strain to address this question. We assessed the gut microbiome and lung metabolome in cKp-infected mice by 16S rRNA sequencing and untargeted liquid chromatography-mass spectrometry, respectively. Our data revealed that cKp infection reduced gut microbiota diversity and altered microbiome composition. Specifically, cKp infection increased the abundance of MWH-CFBk5 and Actinomadura and reduced the abundance of Lachnospiraceae_NK4A136_group, Clostridium sensu_stricto 1, Bifidobacterium, and Intestinimonas at the genus level. Notably, caffeine and caffeine metabolism were significantly affected in the lung by cKp infection. Moreover, Spearman correlation analysis revealed remarkable correlations of specific lung metabolites and bacteria species at the genus level. These findings suggest that cKp infection is linked to gut dysbiosis and alterations in the lung metabolome. This study is of significance for developing innovative gut microbiota-directed therapy for respiratory diseases.