It was not surprising to David Wishart that it took awhile for people to suss out the importance of the news from Edmonton, Alberta, early this year, where a Canadian team completed the first draft of the human metabolome. “Metabolome is a word that no one’s heard of,” Wishart says. But once he tells people that it’s really an extension of clinical chemistry, they’ve been much more impressed. “Its potential for disease diagnosis is much closer to reality than some of the things that will come from the genome,” he adds.
The Human Metabolome Project began formally about two and a half years ago, Wishart says, and started off with a tremendous learning curve that included plenty of technology and literature acquisition. “A huge amount went into finding out what was already known. [We had to] scour the databases, textbooks, and journals around the world,” he says. “There’s a legacy of 100 years of material — it’s a lot to go through.” That wealth of data was part blessing and part curse. In the long run, it will be a time saver to have aggregated the data in one place, Wishart says, but “as far as we could tell it was the only time people had ever tried to collect that information.” If published, he adds, the collection his team wound up with would take some 100,000 pages to print.
But building a giant database of compound information and literature links wasn’t the point of the project. The vision from the beginning was to “facilitate rapid, high-throughput metabolite identification,” Wishart says. To that end, his team put together a spectral library — a repository of spectra from NMR or mass spec experiments that can be used to identify compounds found in blood, urine, other biofluids, or tissues, he adds. “From that they can start identifying compounds not just one at a time, but maybe dozens at a time. … For the last 100 years we’ve been sort of staring at the world through a keyhole. Now we’ve knocked down the door.”
They’ve also set up a host of challenges and opportunities for scientists in the metabolomics field, as well as related disciplines. First off is the need to finish the draft with some thorough editing. Wishart and his crew, among others, will be adding compounds and deleting others as they verify some of the information and add more along the way.
Some of the earliest opportunities to make use of the metabolome data will pop up in disease settings, Wishart says. Armed with this metabolite data, scientists will be able to start using the information to make disease diagnoses, and also begin putting together disease profiles by studying cohorts. Already, drug companies have expressed interest in using the data to monitor drug toxicity. Wishart also sees a clear path to the nutrigenomics field, where metabolite studies may prove an ideal way to looking at food composition.