Body microbes can identify you

Microbial groups we carry in and on our bodies known as the human microbiome have the potential to uniquely identify individuals, much like a fingerprint, scientists say.

Scientists from Harvard TH Chan School of Public Health and colleagues demonstrated that personal microbiomes contain enough distinguishing features to identify an individual over time from among a research study population of hundreds of people.

This study is the first in its kind to rigorously show that identifying people from microbiome data is feasible, suggests that we have surprisingly unique microbial inhabitants.

“Connecting a database of human DNA ‘fingerprints’ to a DNA sample of a human, is the basis for forensic genetics, which is now a decades-old field,” said lead author Eric Franzosa, research fellow in the Department of Biostatistics at Harvard Chan.

“The similar kind of connection is possible with the use of DNA sequences from microbes inhabiting the human body – no human DNA required.

“This is the best way to connect 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,” said Franzosa.

Franzosa used broadly available microbiome data produced through the Human Microbiome Project (HMP), which surveyed microbes in the stool, saliva, skin, and other body sites from up to 242 individuals over a months-long period.

The authors adapted a classical computer science algorithm to combine stable and distinguishing sequence features from individuals’ initial microbiome samples into individual-specific “codes.”

They compared the codes to microbiome samples collected from the same individuals’ at follow-up visits and to samples from independent groups of individuals.