Ectopic colonization of oral bacteria in the intestine drives TH1 cell induction and inflammation

Journal: Science

Published: 2017-10-20

DOI: 10.1126/science.aan4526

Affiliations: 15

Authors: 26

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Research Highlight

Mouth bacteria upsets the bowels

© Burak Karademir/Moment/Getty

© Burak Karademir/Moment/Getty

Bacteria that live in your mouth could end up in the gut and trigger inflammatory bowel disease.

The average person swallows around 1.5 litres of saliva every day, sending a multitude of microbes through the body. Disturbances in gut flora, the gut’s microbial community, are thought to cause conditions such as inflammatory bowel disease (IBD), but tracing the source of inflammation has been difficult.

A team led by researchers from Keio University fed saliva from humans with IBD to healthy mice. After six weeks, they analysed the mice’s faeces and identified the presence of around 20 different human oral bacteria. There was a particular abundance of the Klebsiella — a harmless oral inhabitant when present in healthy humans. The team injected Klebsiella into a new batch of mice and found that it activated immune cells and triggered inflammation in the guts.

Additionally, Klebsiella triggered more inflammation in mice treated with antibiotics, suggesting that medicines that modify gut microbes could make patients more susceptible to bowel disease.

Supported content

  1. Science 358, 359-365 (2017). doi: 10.1126/science.aan4526
Institutions Share
RIKEN Center for Integrative Medical Sciences (IMS), Japan 0.19
Keio University, Japan 0.13
Weizmann Institute of Science (WIS), Israel 0.08
RIKEN Center for Sustainable Resource Science (CSRS), Japan 0.08
NIH National Human Genome Research Institute (NHGRI), United States of America (USA) 0.08
UPMC Children's Hospital of Pittsburgh (CHP), United States of America (USA) 0.08
The University of Tokyo (UTokyo), Japan 0.07
Broad Institute of MIT and Harvard, United States of America (USA) 0.06
Waseda University, Japan 0.05
Osaka City University (OCU), Japan 0.04
Singapore Centre on Environmental Life Sciences Engineering (SCELSE), Singapore 0.04
Okayama University, Japan 0.04
Massachusetts General Hospital (MGH), United States of America (USA) 0.03
Harvard University, United States of America (USA) 0.03
Mansoura University, Egypt 0.02