A reminder that genomics is just getting started
Sometimes I assume the human breadth of knowledge is greater than it is.
This week I read about an announcement about the microbiome that caught me by surprise. A team at Stanford published a paper saying that 99 percent or more of the microbiome consists of organisms that have never been observed by science.
I would have thought this was an area that’s been studied in depth. It’s important for developing treatments for those suffering from Crohn’s and Lupus since there’s evidence that the microbiome plays a big role in these conditions. Also we’re just discovering how interconnected the microbiome is with the immune system and the body’s receptiveness to medical treatments.
The Stanford team suggested that their findings may be due to the fact that few previous scientists have studied DNA that’s freely circulating in blood plasma.
It reminds me of Craig Venter’s ocean sampling project from the early 2000s. Who knows what they’ll find next.
Here is the abstract of the study:
Blood circulates throughout the human body and contains molecules drawn from virtually every tissue, including the microbes and viruses which colonize the body. Through massive shotgun sequencing of circulating cell-free DNA from the blood, we identified hundreds of new bacteria and viruses which represent previously unidentified members of the human microbiome. Analyzing cumulative sequence data from 1,351 blood samples collected from 188 patients enabled us to assemble 7,190 contiguous regions (contigs) larger than 1 kbp, of which 3,761 are novel with little or no sequence homology in any existing databases. The vast majority of these novel contigs possess coding sequences, and we have validated their existence both by finding their presence in independent experiments and by performing direct PCR amplification. When their nearest neighbors are located in the tree of life, many of the organisms represent entirely novel taxa, showing that microbial diversity within the human body is substantially broader than previously appreciated.
Full text in PNAS: http://www.pnas.org/content/early/2017/08/21/1707009114
