With annually 2.56 million deaths worldwide, pneumonia is one of the leading causes of death. Most frequent causative pathogens are Streptococcus pneumoniae and influenza A virus. Lately, the interaction between pathogens, the host and its microbiome gained more attention. A healthy microbiome is known to enhance the immune response towards pathogens, however, our knowledge on how infections affect the microbiome is still scarce. In this study, a meta-omics approach was used to investigate the impact of S. pneumoniae and influenza A virus infection on structure and function of the respiratory and gastrointestinal microbiomes of mice. In particular, the taxonomic composition of the respiratory microbiome was less affected by bacterial colonization and viral infection compared to S. pneumoniae infection. Pneumococcal pneumonia led to reduction of bacterial families and lower diversity in the respiratory microbiome, whereas diversity/richness was unaffected following H1N1 infection. Within the gastrointestinal microbiome we found exclusive changes in structure and function depending on the pneumonia inducing pathogen. Exemplarily, increased abundance of Akkermansiaceae and Spirochaetaceae, as well as decreased amounts of Clostridiaceae in response to S. pneumoniae infection, while increased presence of Enterococcaceae and Staphylococcaceae was specific for viral-induced pneumonia. Investigation of the intestinal microbiomes functional composition revealed reduced expression of flagellin and rubrerythrin and increased levels of ATPase during pneumococcal infection, while increased amounts of acetyl-CoA acetyltransferase and, enoyl-CoA transferase were unique after H1N1 infection. The identification of specific taxonomical and functional profiles during infection with a respective pathogen could deliver new insights in the role of the microbiome during disease and be beneficial for discrimination of pneumococcal- or viral-induced pneumonia.