The ambivalent role of Bacteroides in enteric infections

In "Trends in Microbiology", Alexander Westermann and Elise Bornet discuss the interplay of these gut bacteria with the intestinal immune system and invading pathogens.

Bacteria of the genus Bacteroides are among the predominant members of the human gut microbiota. Outside the digestive tract, they occasionally act as infectious germs. However, as colonizers of the colon lumen and mucous layer, they can protect against infection by providing colonization resistance against enteric pathogens.

Scientific studies nevertheless yield conflicting results regarding the contributions of Bacteroides to host health versus disease, arguing that the role of these bacteria in intestinal infections is more nuanced than anticipated. While the microbes initially provide colonization resistance to pathogen invasion, they can be exploited by the same pathogens to establish infection.

Bacteroides: A double-edged sword for enteric infection

In their comprehensive review recently published in Trends in Microbiology, research group leader Alexander Westermann and PhD student Elise Bornet from the Helmholtz Institute for RNA-based Infection Research (HIRI) discuss the different facets of the interaction of Bacteroides with the intestinal immune system.

In their analysis, the researchers merge findings from infection studies with various enteropathogens –– i.e. pathogens that cause intestinal diseases. They also illustrate how cutting-edge transcriptomics (the study of all RNA molecules within a cell) may help disentangle the molecular basis of the divergent role of Bacteroides in either protecting against or promoting infection.


Elise Bornet, Alexander J. Westermann. The ambivalent role of Bacteroides in enteric infections. Trends in Microbiology, December 7, 2021. DOI: https://doi.org/10.1016/j.tim.2021.11.009


Britta Grigull

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Dr Britta Grigull