Researchers say gut bugs could change people’s blood type. 

In a groundbreaking study published in Nature Microbiology, a team of Danish and Swedish researchers has discovered that enzymes derived from the gut bacterium Akkermansia muciniphila can transform type A and B blood into type O, the universal blood type used in transfusions. 

This finding could significantly boost global supplies, address persistent shortages and enhance the safety of blood transfusions.

Blood transfusions are critical in medical procedures, but the suitability of blood for transfusion depends on compatible blood groups. 

Mismatched blood transfusions can provoke severe immune reactions, which can be fatal. The universal donor blood, type O, is in high demand because it can be received by individuals of any blood group.

A recent study shows that A. muciniphila produces a unique combination of enzymes that effectively removes specific sugar chains - known as glycans - from the surface of red blood cells. 

These glycans determine an individual's blood type. By stripping these markers from type A and B blood, the enzymes convert them into type O, which lacks these surface markers.

“We have identified structurally unique enzymes that efficiently target and remove not only the known antigens but also newly discovered variants,” says researcher Dr Maher Abou Hachem.

This implies that the enzyme cocktail is effective even on A and B antigens that were previously unrecognised, making the process potentially applicable to a wider range of blood types than earlier methods.

“The enzymatic conversion of blood group antigens offers a promising route to increase the availability of universal O blood, addressing a significant bottleneck in blood transfusion services worldwide,” says co-researcher Martin L Olsson.

However, while the enzyme treatment has shown to reduce mismatch reactions in tests, especially with B group blood, the researchers have noted that further enhancement is needed for group A blood conversion. 

“Although the results are promising, more work will be needed to refine the enzyme's effectiveness across a broader range of A group antigens,” Olsson added.

If these obstacles can be overcome, the researchers hope that their findings could lead to practical applications in medical facilities, potentially transforming how blood stocks are managed and making transfusions safer and more accessible to patients worldwide. 

The full study is accessible here.