Gut immune maturation depends on colonization with a host-specific microbiota


Hachung Chung, Sünje J Pamp, Jonathan A Hill, Neeraj K Surana, Sanna M Edelman, Erin B Troy, Nicola C Reading, Eduardo J Villablanca, Sen Wang, Jorge R Mora, Yoshinori Umesaki, Diane Mathis, Christophe Benoist, David A Relman, and Dennis L Kasper. 2012. “Gut immune maturation depends on colonization with a host-specific microbiota.” Cell, 149, 7, Pp. 1578-93.


Gut microbial induction of host immune maturation exemplifies host-microbe mutualism. We colonized germ-free (GF) mice with mouse microbiota (MMb) or human microbiota (HMb) to determine whether small intestinal immune maturation depends on a coevolved host-specific microbiota. Gut bacterial numbers and phylum abundance were similar in MMb and HMb mice, but bacterial species differed, especially the Firmicutes. HMb mouse intestines had low levels of CD4(+) and CD8(+) T cells, few proliferating T cells, few dendritic cells, and low antimicrobial peptide expression--all characteristics of GF mice. Rat microbiota also failed to fully expand intestinal T cell numbers in mice. Colonizing GF or HMb mice with mouse-segmented filamentous bacteria (SFB) partially restored T cell numbers, suggesting that SFB and other MMb organisms are required for full immune maturation in mice. Importantly, MMb conferred better protection against Salmonella infection than HMb. A host-specific microbiota appears to be critical for a healthy immune system.