John Hawks highlights a new article in today’s Science, Metagenomic Analysis of the Human Distal Gut Microbiome. This goes nicely with the posts here recently on the topic of how our microbes affect our health and weight (part I; part II). A bit of discussion of the new article below…
First, I want to briefly mention what “metagenomics” means. There’s a nice overview of it here on wikipedia. Basically, instead of sequencing and assembling a genome one at a time, you take a raw sample (such as dental plaque, sea water, soil, or fecal material, in this case), isolate the DNA, sequence it all, and then piece it together. The advantage is that you don’t need a pure culture of an organism in order to study it, making it ideal for organisms that we currently can’t culture using traditional means. In the new paper, the authors used this strategy to examine the gut “microbiome” of 2 study participants.
But as John points out, comparisons of 2 people is just the tip o’ the iceberg. It’s an interesting start (and, not too surprisingly, they already found some significant differences between the two), but it’ll take a lot more work until we get to the point where we have the power to detect reproducible associations between a particular “poo print” and disease status. The paper mentions this, but is optimistic:
Future studies are needed to provide deeper coverage of the microbiome and to assess the effects of age, diet, and pathologic states (e.g., inflammatory bowel diseases, obesity, and cancer) on the distal gut microbiome of humans living in different environments. Periodic sampling of the distal gut microbiome (and of our other microbial communities) may provide insights into the effects of environmental change on our “microevolution.” The results should provide a broader view of human biology, including new biomarkers for defining our health; new ways for optimizing our personal nutrition; new ways for predicting the bioavailability of orally administered drugs; and new ways to forecast our individual and societal predispositions to disorders such as infections with pathogens, obesity, and misdirected or maladapted host immune responses of the gut.
It’s exciting that we’ll soon know a whole lot more about the life forms that we’re most intimately in contact with.
Gill et al. 2006. Metagenomic Analysis of the Human Distal Gut Microbiome. Science. 312:1355-1359.