The Bacteria That Could Turn Any Blood Into a Universal Donor

Note: This technology remains in the experimental stage and has not yet been proven safe or effective in human patients. It may take years of testing before it could be used in hospitals.

This should’ve been bigger news than it was, but for some reason, I couldn’t find much about it online. So here I am, writing about it instead. Now, imagine a world where blood shortages didn’t exist.
Where emergency rooms never paused to check compatibility and a single type of blood could save everyone.

This isn't a bizarre dream I had once after eating too much cheese before bed (causes nightmares, look it up!), it’s the promise of a gut-dwelling bacteria with an oddly miraculous talent: turning nearly any blood type into universal donor blood.

And yes, it’s as weird and wonderful as it sounds.

A Crash Course in Blood Types

You’ve probably heard of A, B, AB, and O, there’s also positives and negatives.
But what actually makes them different you might wonder?

It all comes down to antigens these little sugar-based proteins on the surface of red blood cells. If your body sees a foreign antigen, it completely panics. Cue the immune response, inflammation, and in the worst cases, a fatal rejection all because you didn’t have a safe panic room to hide in.

That’s why it’s so important that blood transfusions have to match.
But not always it turns out.

O negative blood doesn’t have A or B antigens, or the Rh factor.
It’s the universal donor, safe for almost anyone.
The problem is that only about 7% of people have it, and the demand always outpaces supply.

So that’s the problem that the researchers at the University of British Columbia decided to focus on, and in the process recently discovered a strain of gut bacteria that produces enzymes capable of stripping antigens off red blood cells.

Aka, they found an enzyme that could erase a blood type’s identity, leaving behind plain old, untagged red cells that the immune system won’t attack or panic about.

It’s like turning a name-brand blood cell into a generic one by stripping off that identifying part.

When added to type A or B blood in lab tests, these enzymes “shaved off” the antigens quickly and cleanly. So all the red blood cells looked and acted like type O afterwards.

This Was in Our Guts the Whole Time?

Yes! That’s the fun of this discovery.

These bacteria (easily found in our digestive tracts) evolved to digest mucins, which are sugar proteins that look sort of similar in structure to blood antigens.

They weren't trying to change medicine, they were just trying to eat some sugar (who wasn’t, am I right?), but in doing so, they revealed a fancy little mechanism that could solve one of healthcare’s longest-standing bottlenecks.

If we can safely harness and scale that enzyme, blood type might become almost completely irrelevant when we’re talking about transfusions.

The Promise and the Caution

It would be really cool if every hospital could stock the same blood. Emergency care in rural areas would get faster, and safer.

Disaster zones and battlefield medics carry fewer risks to helping others in state of emergency. Transfusions would become simpler, cheaper, and far more accessible.

But we’re not there yet, so maybe I should slow down on my dreaming. Classic me, reading about something then jumping light-years ahead.

Scientists still need to confirm that red cells aren’t damaged in the process, prove no residual antigens remain that could trigger immune responses, and also test it on diverse patient populations so they know it’s not a one-off or only works on some and not others.

Still though, early data looks incredibly promising.
And if it checks out, this could be the biggest advancement in blood medicine since Karl Landsteiner discovered the A/B/O system in 1901!!

A Brief History of Blood Compatibility (and Chaos)

Before we understood blood types, transfusions were a gamble.

In the 1600s, doctors tried giving patients lamb blood. (Spoiler alert: it didn’t work.)
In the 1800s, human-to-human transfusions were erratic some were miraculous, while some were deadly.

It wasn’t until the early 20th century that we learned not all blood is created equal. Landsteiner’s work laid the foundation, and the discovery of Rh factor followed in 1937.

But for all that progress, blood compatibility is still a logistics nightmare.
Crossmatching takes time, and O-negative is perpetually scarce, people literally die waiting for the right type to pop up.

This bacterial enzyme could end that though.

Low-resource countries with limited screening options could dramatically reduce transfusion errors, and ambulances could stock one blood supply for everyone. Pandemics or crises would no longer cripple the blood system with shortages, all while military and disaster teams would gain a simple, universal tool.

And in a world edging closer to personalized medicine, this feels ironically elegant: a single, universal solution.

The Rise of Microbial Medicine

This isn't the first time bacteria have stepped in to help us.

Gut microbes have been linked to mood regulation, immune system strength, inflammation control, even decision-making and appetite. It’s why I’ve written about it before in The Hidden Intelligence of Your Gut.

Now these cute little guys are helping rewrite transfusion science.

In fact, scientists are increasingly turning to the microbiome for answers.
It turns out nature has been solving problems all along, we just had to look a little closer and stop messing with what it did already on its own.

Curious About Your Own Blood Type?

You don’t have to wait for the future to engage with your blood biology.
Home Blood Typing Kit on Amazon…know your blood type in 5 minutes. No lab required, just a few drops and you’re done. (I’m A+!)

Because if we’re going to rewrite the rules of blood, you might as well know which chapter you came from.
Sometimes science is microscopic and it’s tucked away in your gut, digesting lunch and casually solving one of humanity’s biggest medical problems.

This little bacteria doesn’t know it's important.
But it might save millions of lives.

Not bad for a bacteria.