Diarrheal Severity can Depend on an Individual’s Blood Type

People who have blood type A, may have severe diarrhea when compared to other blood types, such as O or B, finds a new study. The severity of the diarrheal symptoms associated with E. coli infection have been found to be directly linked to blood type A. The findings of this study are published in the Journal of Clinical Investigation

E.coli mostly associated with child deaths in underdeveloped areas and "travelers’ diarrhea" have been found to affect people with A blood group more severely than other blood groups.

A new vaccine can be devised to target that specific protein that latches on onto intestinal walls of people with blood type A. This can help prevent severe diarrhea in people with A Blood type.

Senior author of the study, James Fleckenstein said "We think this protein is responsible for this blood-group difference in disease severity," he also adds that "A vaccine targeting this protein would potentially protect the individuals at highest risk for severe disease."

The study was a collaborative effort between researchers at Johns Hopkins University, the National Institutes of Health (NIH), and the Naval Medical Research Center.

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Enterotoxigenic E. coli

Enterotoxigenic specific E. coli have been previously associated with hundreds of diarrheal cases and have resulted in deaths especially in children from underdeveloped countries.

It has also been associated with people who have been traveling to developing countries.

People who are infected with this bacteria, tend to suffer from fatal, cholera-like, watery diarrhea. The symptoms vary so much that some have symptoms but recover easily, while some don’t get sick at all.

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Study Procedure

The lead author Fleckenstein lead the investigation by finding out whether a specific blood type influenced diarrhea severity by examining what happened to people of different blood types who drank a cup of water laced with E. coli.

In the study, the researchers infected people with a dose of an E. coli strain initially isolated from a person in Bangladesh with severe, cholera-like diarrhea to observe what happened to them. They did this for five days and those who had moderate to severe diarrhea were treated with antibiotics.

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Results :

Blood samples from 106 people were studied. In this, they found that participants who had blood type A got sick sooner and more seriously than those of who had other blood groups. Eight out of ten people developed diarrhea that required treatment, as compared to another half of people with blood group B or O. 

It was found that the bacteria produced a specific protein which stuck to A-type sugars - but not B- or O-type sugars.

"I don’t want anyone to cancel their travel plans to Mexico because they have to type A blood," Kuhlmann said. "Or the converse: I don’t want anyone to think they’re safe because their blood group is not A. There are a lot of different species of bacteria and viruses that can cause diarrhea, so even though this blood-group association is strong, it doesn’t change your overall risk. You should continue taking the same precautions whatever your blood type."

Proper handwashing can protect the people from diarrheal diseases irrespective of blood groups.

The protein identified in this study has been found in many strains, so developing a vaccine for one particular strain will not be effective thereby a universal vaccine capable of preventing it against other strains have to be prepared.

Reference:

1. Your blood type might make you more likely to get traveler’s diarrhea - (https://www.sciencenews.org/article/your-blood-type-might-make-you-more-likely-get-travelers-diarrhea)
2. "Pardeep Kumar, F. Matthew Kuhlmann, Subhra Chakroborty, et. al", Pardeep Kumar, F. Matthew Kuhlmann, Subhra Chakroborty, (2018) https://doi.org/10.1172/JCI97659

Source-Medindia