Enzymes secreted by human gut bacteria may provide an answer for
converting donated blood of any group to O blood group
- Scientists identify enzymes secreted by bacteria in human gut that
can convert A, B and AB group blood to O group blood, which is universal
- O- Group blood can be transfused to persons of other blood groups in
a medical emergency if the matching blood group is not available
- Finding a safe, efficient and economical way to convert other blood
groups to O group will be useful to overcome shortage of blood during
times of emergency and disaster
which is the universal donor, according to research undertaken by Stephen Withers, Ph.D.,
and a colleague at his institution, the University of British Columbia (UBC),
who uses metagenomics to study ecology
findings of the study will be presented at the 256th National Meeting &
Exposition of the American Chemical Society (ACS), the world's largest
scientific society in August 2018. The meet features more than 10,000
presentations on diverse science topics.
‘Finding a safe efficient and economical method to convert other blood groups (A,B and AB) to group O blood (universal donor) can help overcome shortage of blood during medical emergencies’
"We have been particularly interested in enzymes that
allow us to remove the A or B antigens from red blood cells," Stephen
Withers says. "If you can remove those antigens, which are just simple
sugars, then you can convert A or B to O blood."
Finding a Way to Convert
Other Group Blood to Universal Donor Group O
current study was undertaken to look for answers to overcome serious shortage
of blood such as occurred during the recent raging storms along the U.S. East
Coast, prompting the Red Cross to issue an urgent call for blood donations
Easy availability of O group
universal donor blood in such situations could help save several hundred lives.
studies have been unsuccessful in finding efficient selective enzymes that are also
safe and economical in achieving this.
- To hasten the process, Withers
worked with a colleague in metagenomics
where the DNA of millions of
organisms found in the environment are directly extracted and mixed
together for analysis,
overcoming the need for separate cultures and isolation of specific
Withers, "This is a way of getting that genetic information out of the
environment and into the laboratory setting and then screening for the activity
we are interested in".
mixed up DNA of various organisms were analyzed using E coli bacteria to selectively look
for DNA containing genes that code for enzymes that can remove sugar
residues from a molecule.
is because A and B antigens found on the red blood cells of persons with A and
B group blood respectively are in fact simple sugars. Removal of these antigens
from the red blood cells will cause the blood to lose the A or B group antigens
and become O group.
- Withers and his team had considered
working with DNA of leeches and mosquitoes, organisms known to degrade
blood and finally found the enzymes
they were looking for in human gut bacteria
- The enzymes are used by gut
bacteria to remove the sugars from the mucus lining (mucin) of
the intestine, to provide energy for their activities
- The newly identified family of
enzymes was 30 times more effective
at removing blood group antigens on red cells than previously
am optimistic that we have a very interesting candidate to adjust donated blood
to a common type," Withers says. "Of course, it will have to go
through lots of clinical trials to make sure that it doesn't have any adverse
consequences, but it is looking very promising."
Future Research Plans
- Withers is currently working with
colleagues at the Centre for Blood Research at UBC to validate the results
of their study and test the enzymes on a larger scale for possible
clinical testing in the future
- Additionally, he plans to undertake
directed evolution, a protein engineering technique that mimics natural
evolution, with the aim of producing the most efficient sugar-removing
Why O Group Is Universal
Donor - About Blood Groups in Brief
are 4 blood groups namely A, B, AB and O. Red blood cells of persons with A, B
and AB blood group have A, B and both A and B antigens respectively on their
surface. O group persons have no antigens on their red cells.
persons with A, B or O group receive mismatched blood, they can develop
potentially fatal transfusion reaction. AB group persons can however receive
A,B and O blood and are termed universal recipients (since they have both A and
B antigens and will not develop a transfusion reaction).
O group blood does not have any antigens on its red cells, it cannot induce an
immune system mediated transfusion reaction in the recipient and is termed
universal donor blood and can be safely given to persons having other blood
groups, especially in an emergency.
conclusion, should the gut bacterial enzymes prove to be a safe, effective and
a cheap way to convert donated blood to universal group O blood, and become
approved for clinical use, it could solve the problems of shortage of
lifesaving blood and be a game changer in managing medical emergencies in
- Gut bacteria provide key to making universal blood - (https://phys.org/news/2018-08-gut-bacteria-key-universal-blood.html)