Host Immunity Influences the Composition of Murine Gut Microbiota

Gut microbiota influences several aspects of immunity, and its disturbance is linked with several immune-mediated disorders. However, conversely, whether inherently disturbed canonical Th1 (proinflammatory) and/or Th2 (anti-inflammatory) immune pathways modify the host microbiome is not sufficiently studied. In this study, we first characterized the humoral and cytokine adaptive immunity and Th1/Th2/Th17 polarization under unchallenged conditions in wild-type BALB/c and C57BL/6 mice, in mice with deficiencies in Th2 responses (IL-4Ra-/- and IL-33-/- mice) as well as severely immunocompromised mice with a deficiency in both Th1 and Th2 responses (NOD scid gamma, NSG mice). We further characterized the immunocompetency-associated caecal microbiota using 16S rRNA gene profiling to understand the microbiota-driven immunologic and metabolic activities in these mouse genotypes.