Microbes can help identify people, like DNA, fingerprints – study

The sets of microbes people carry in their bodies are as unique as fingerprints, a new study shows. So law enforcers may be provided with yet another tool for identifying criminal suspect.

Researchers from the Harvard School of Public Health studied the stool, saliva, skin and other bodily sites from 242 individuals over a one-year period. The scientists eventually came to the conclusion that it is possible to identify someone from their microbiomes – the variety of microbes people carry in their bodies. The findings were published in the PNAS journal.

“Right now, it’s a little bit of a Wild West as far as microbiome data management goes,” Curtis Huttenhower, from Harvard University, who led the study, said in a press release. “As the field develops, we need to make sure there’s a realization that our microbiomes are highly unique.”

The results showed that the microbiome codes from each person were unique and that a person’s “microbial community” remained stable over the whole period it was studied. The codes constructed from gut samples were particularly stable. The researchers found more than 80 percent of the individuals were recognizable up to a year after the sampling period had ended.

“Linking a human DNA sample to a database of human DNA ‘fingerprints’ is the basis for forensic genetics, which is now a decades-old field. We’ve shown that the same sort of linking is possible using DNA sequences from microbes inhabiting the human body—no human DNA required,” said lead author Eric Franzosa.

Your gut #microbiome has a unique personal signature http://t.co/ETTAtKrUJG@PNASNews#indivmedpic.twitter.com/IJ5b8JtNZM

— Eric Topol (@EricTopol) May 11, 2015

“This opens the door to connecting human microbiome samples between databases, which has the potential to expose sensitive subject information—for example, a sexually-transmitted infection, detectable from the microbiome sample itself,” he added.

Mark Gerstein, from Yale University, who wasn’t involved in the study, believes the discovery could be used to track terrorists. This could be achieved by looking for microbe traces they leave behind, for example in caves and other remote places.

It is not known how well the algorithm will work if it is exposed to a larger section of the population. However, the researchers say their code would be able to pick somebody out of a group of between 500 to 1000 people. “I would expect that number to get bigger in the future as we get more data and better data and better coding strategies,” Huttenhower said.

However, the discovery could raise potential privacy concerns for those involved in the research projects.

“Although the potential for any data privacy concerns from purely microbial DNA is very low, it’s important for researchers to know that such issues are theoretically possible,” said Huttenhower.

“Perhaps even more exciting are the implications of the study for microbial ecology, since it suggests our unique microbial residents are tuned to the environment of our body—our genetics, diet, and developmental history—in such a way that they stick with us and help to fend off less-friendly microbial invaders over time,” Huttenhower added.