Researchers Find Gut Bacteria that Can Change Type A Blood to Type O

Blood Donations

For many people living with a rare disease such as Beta thalassemia, Hemophilia, Aplastic Anemia, Myelodysplastic syndromes, Acute Promyelocytic leukemia, and others, blood transfusions are not uncommon. For some, they are a part of their normal routine. For others, it is an unexpected necessity during an emergency. For others still, they may never need a transfusion, but will be lifelong donors. Unfortunately, despite the thousands of kind souls who provide donations, there is a constant shortage in the United States and other areas of the world.

It’s estimated that in just a singular day, hospitals in the US use approximately 35,000 pints of blood. This includes routine blood transfusions, emergency surgeries, and scheduled operations.

One of the issues is that there are four different types of blood- A, B, AB, and O. When someone with A type blood receives type B, the blood antigens spark an immune response and the red blood cells are attacked. This means if you have type A you can’t receive type B and vice versa. However, anyone can receive the O type because the sugar antigens that cause this response aren’t present in type O. For this reason, type O is called the universal blood type.

Not only is it convenient that anyone can receive a type O infusion, type O is essential in emergency situations when there is not time to test the patient’s blood type.

Researchers have investigated converting type A (which is the most common of all) to type O in the past, to no avail. But a new discovery has brought new promise to this idea, which could literally save lives.

A New Discovery

At first, researchers were attempting to remove the “A-defining” antigens from the type A blood. The problem is, to do this they used enzymes which weren’t very efficient and it couldn’t be done economically. This research went on for 4 years.

But Stephen Withers, from the University of British Columbia had a new idea that had never before been examined. He and his team began looking at enzymes among human gut bacteria. They thought this might work because the gut is lined with mucins, a sugar-protein combination that is very similar to the sugar antigens found in type A blood. There are specific enzymes in the gut that digest mucins, and the team began investigating the possibility of using these enzymes to convert type A.

At first, the results were discouraging. But soon, the research team found something exciting. They combined two enzymes found in the gut bacterium Flavonifractor plauti. By adding small amounts of both of these enzymes to type A blood, they were able to effectively remove the sugar antigens.

While this novel finding is extremely exciting, researchers make it clear there is still a lot of work that needs to be done. A problem that arose in previous studies was that not all of the antigens had been removed. The team needs to ensure that 1- all of the antigens are gone and 2- nothing else has been inadvertently altered in the blood, which could cause serious problems.

That said, if this research continues to produce positive results, in could completely change the game for blood donations and rare disease patients who rely on transfusions.

Type A blood in the US comprises approximately 1/3 of the entire blood supply. If all of this blood could be converted to type O, the availability of the “universal” blood type would nearly double. The researchers have been focused on type A because it is the most common, but this study could potentially be expanded to type B blood as well. This too, would significantly increase the availability of type O.

These findings have been published in Nature Microbiology.

“This is a first, and if these data can be replicated, it is certainly a major advance.”

You can read more about these novel findings here.


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