Selected commensals educate the intestinal vascular and immune system for immunocompetence

Microbiome. 2022 Sep 28;10(1):158. doi: 10.1186/s40168-022-01353-5.


Background: The intestinal microbiota fundamentally guides the development of a normal intestinal physiology, the education, and functioning of the mucosal immune system. The Citrobacter rodentium-carrier model in germ-free (GF) mice is suitable to study the influence of selected microbes on an otherwise blunted immune response in the absence of intestinal commensals.

Results: Here, we describe that colonization of adult carrier mice with 14 selected commensal microbes (OMM12 + MC2) was sufficient to reestablish the host immune response to enteric pathogens; this conversion was facilitated by maturation and activation of the intestinal blood vessel system and the step- and timewise stimulation of innate and adaptive immunity. While the immature colon of C. rodentium-infected GF mice did not allow sufficient extravasation of neutrophils into the gut lumen, colonization with OMM12 + MC2 commensals initiated the expansion and activation of the visceral vascular system enabling granulocyte transmigration into the gut lumen for effective pathogen elimination.

Conclusions: Consortium modeling revealed that the addition of two facultative anaerobes to the OMM12 community was essential to further progress the intestinal development. Moreover, this study demonstrates the therapeutic value of a defined consortium to promote intestinal maturation and immunity even in adult organisms. Video Abstract.

Keywords: Asymptomatic infection; Blood vessel development; C. rodentium; Colonization resistance; Commensal imprinting; Endothelial cells; Enteric pathogen; Genome-guided microbiota; Intestinal maturation; Microbial consortia; Neutrophils; Oligo-Mouse-Microbiota.

Publication types

  • Video-Audio Media
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Citrobacter rodentium* / physiology
  • Immune System
  • Immunocompetence
  • Intestinal Mucosa*
  • Intestines
  • Mice