WASHINGTON, May 11 -- The communities of microbes that live in and on our bodies, collectively known as the human microbiome, have the potential to uniquely identify people, much like a fingerprint, a U.S. study said Monday.

Eric Franzosa of the Harvard University and colleagues used publicly available microbiome data produced through the U.S. government-funded Human Microbiome Project, which surveyed microbes in the stool, saliva, skin, and other body sites from up to 242 individuals over a period of months.

They developed a computer algorithm to combine stable and distinguishing sequence features from individuals' initial microbiome samples into individual-specific "codes" and then compared them to samples collected from the same individuals at follow-up visits.

The results showed that the codes were unique among hundreds of individuals, and that a large fraction of individuals' microbial " fingerprints" remained stable over a one-year sampling period.

The codes constructed from gut samples were particularly stable, with more than 80 percent of individuals identifiable up to a year after the sampling period.

The study, the first to rigorously show that identifying people from microbiome data is feasible, suggested that humans have surprisingly unique microbial inhabitants.

Linking a human DNA sample to a database of human DNA " fingerprints," said Franzosa, 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," he said in a statement.

"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."

The findings were published online in the U.S. journal Proceedings of the National Academy of Sciences.