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Travelers’ Diarrhea Has A Type

If your blood type is A, you better pack some diarrhea medication when traveling to developing countries.

Are you getting ready to go on a trip? Are you all prepared? Luggage? Travel first-aid kid?

And does that have everything you need?

Ibuprofen, band-aids, antiseptic wipes? Oh, and diarrhea medication. Especially if you have a particular blood type, you might need to be especially prepared to deal with diarrhea.

It turns out people with type A blood are more likely to get sick from a specific strain of E. coli bacteria commonly seen in people living in or visiting developing countries. See, blood type groups are determined by the different sugars found on the surfaces of your red blood cells and elsewhere-people with type A blood have different sugar molecules than people with type B or O blood.

Researchers found that this specific strain of E. coli secreted a protein that attached to the type A sugars found on intestinal cells of people with type A blood. This protein also sticks to the E. coli bacteria, essentially fastening the bacteria and intestinal cells together, which makes it easier for the E. coli to inject its diarrhea-causing toxins into the cell.

The researchers did a study to test that: they had a hundred and six volunteers drink water laced with E. coli they isolated from a person in Bangladesh suffering from severe diarrhea. Eighty-one percent of the volunteers with type A blood developed moderate to severe diarrhea, compared to only about fifty percent with blood types B or O.

Thank you to Monika Fischer of Indiana University for reviewing this episode's script.

Sources And Further Reading:



  • Pardeep Kumar, F. Matthew Kuhlmann, Subhra Chakroborty, A. Louis Bourgeois, Jennifer Foulke-Abel, Brunda Tumala, Tim J. Vickers, David A. Sack, Barbara DeNearing, Clayton D. Harro, W. Shea Wright, Jeffrey C. Gildersleeve, Matthew A. Ciorba, Srikanth Santhanam, Chad K. Porter, Ramiro L. Gutierrez, Michael G. Prouty, Mark S. Riddle, Alexander Polino, Alaullah Sheikh, Mark Donowitz, James M. Fleckenstein. Enterotoxigenic Escherichia coli blood group A interactions intensify diarrheal severity. Journal of Clinical Investigation, 2018; DOI: 10.1172/JCI97659
  • Washington University School of Medicine. "Blood type affects severity of diarrhea caused by E. coli: Researchers ID protein responsible for blood-group difference." ScienceDaily. May 17, 2018. Accessed August 8, 2018.


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