Commensal microbes provide first line defense against Listeria monocytogenes infection

J Exp Med. 2017 Jul 3;214(7):1973-1989. doi: 10.1084/jem.20170495. Epub 2017 Jun 6.


Listeria monocytogenes is a foodborne pathogen that causes septicemia, meningitis and chorioamnionitis and is associated with high mortality. Immunocompetent humans and animals, however, can tolerate high doses of L. monocytogenes without developing systemic disease. The intestinal microbiota provides colonization resistance against many orally acquired pathogens, and antibiotic-mediated depletion of the microbiota reduces host resistance to infection. Here we show that a diverse microbiota markedly reduces Listeria monocytogenes colonization of the gut lumen and prevents systemic dissemination. Antibiotic administration to mice before low dose oral inoculation increases L. monocytogenes growth in the intestine. In immunodeficient or chemotherapy-treated mice, the intestinal microbiota provides nonredundant defense against lethal, disseminated infection. We have assembled a consortium of commensal bacteria belonging to the Clostridiales order, which exerts in vitro antilisterial activity and confers in vivo resistance upon transfer into germ free mice. Thus, we demonstrate a defensive role of the gut microbiota against Listeria monocytogenes infection and identify intestinal commensal species that, by enhancing resistance against this pathogen, represent potential probiotics.

MeSH terms

  • Animals
  • Anti-Bacterial Agents / administration & dosage
  • Anti-Bacterial Agents / pharmacology
  • Antibiosis / drug effects
  • Feces / microbiology
  • Gastrointestinal Microbiome / physiology*
  • Host-Pathogen Interactions / genetics
  • Humans
  • Immunocompromised Host
  • Intestines / drug effects
  • Intestines / microbiology*
  • Listeria monocytogenes / drug effects
  • Listeria monocytogenes / physiology*
  • Listeriosis / genetics
  • Listeriosis / microbiology*
  • Listeriosis / mortality
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Survival Analysis
  • Survival Rate
  • Time Factors


  • Anti-Bacterial Agents