A team from the University of British Columbia (UBC) caused quite the stir this week at one of the American Chemical Society’s (ACS) annual gatherings in Boston. As spotted by BBC News, it appears that they’ve found an efficient way to use gut bacteria enzymes to change blood types from one to the other.
This ability has been known about for some time. As an example, the very same team announced back in 2015 that enzymes used by Streptococcus pneumoniae could manage this.
The UBC team, however, have seemingly narrowed down the most effective method for achieving this feat to date. In order to understand how it works, though, here’s a quick recap of how blood groups come about.
Blood types come in four main groups: A, B, AB, and O. Bequeathed to you by your inherited genes, they are determined by the presence of proteins named antigens on the surface of your red blood cells.
These antigens come in a variety of forms. Per the UK’s National Health Service (NHS), blood group A features A-type antigens on the red blood cells, along with anti-B antibodies – the handcuffs that pin down and identify threats to the immune system – within the plasma.
Blood group B has the opposite antigen and antidote situation to group A. Those with AB blood have both A and B antigens, but no antibodies in the plasma. Those in blood group O have anti-A and anti-B antibodies in the plasma, but no A or B antigens on their red blood cells.
Each of these types can also be positive or negative for another antigen, known as the Rhesus factor. That means there are eight distinct blood types.
You can’t mix blood types up. If you do so, the various antibodies will recognize their requisite antigens as threats and try to take each other out. That’s why O blood type donations are so important: as their red blood cells contain no A or B antigens, the antibodies of other groups won’t attack them.