Bacteria In Your Body Is Still Unknown

Almost All of the Bacteria In Your Body Is Still Unknown to Science

New DNA research finds an that we all contain multitudes of as-yet undiscovered microbes.

Getty Ian Cuming
 
By Avery Thompson

Our bodies are not our own, at least not entirely. They're filled with tiny bacteria and other microorganisms, collectively called our microbiome. This small ecosystem features bacteria on our skin, in our mouths, in our guts, and nearly every corner of our bodies, and they perform crucial tasks that help keep us alive. For instance, bacteria in your intestines are the reason you can digest complex carbohydrates like starch.

Understanding this microbiome is key for doctors and scientists looking to improve human health. Scientists thought they understood most of the microbiome's mysteries, but new research from Stanford suggests they're almost completely in the dark. A new study of DNA fragments found in the human bloodstream found that around 99 percent of that DNA was previously undiscovered.

Originally, the researchers were trying to find an easier method for predicting whether an organ transplant patient would regent the organ. The team realized that they could get a comprehensive survey of all the DNA in a patient's system just by looking at the free DNA floating in their bloodstream.

The team collected samples from 156 people undergoing organ transplants, and found they could identify DNA from the patient, from the organ donor, and from the bacteria living inside the patient's body. But they found something strange: In each case, 99 percent of the DNA they collected failed to match anything in their database, meaning it was completely unknown to science.

"We found things that are related to things people have seen before, we found things that are divergent, and we found things that are completely novel," says study author Stephen Quake.

The team spent the next few years studying and cataloguing all the DNA fragments they could find. They found a large chunk of new bacterial DNA, and DNA from the torque teno family of viruses. "We've doubled the number of known viruses in that family through this work," said Quake.

The team is planning to repeat the experiment for different animal species, hoping to find even more new microorganisms. Their research could spot future infectious diseases before they happen or help doctors identify the bacteria or virus responsible. And this discovery opens up a brand new avenue of research for scientists looking to understand the microbiome.