|Source: Discover Magazine|
The human microbiome is estimated to include 10x cells... your cells, and your genetic data, are the minority of your whole. Understanding how the colony of diverse organisms that is the human body work together is considered critical to understanding health, and in particular the immune system.
Sequencing the microbiome will be critical to this larger picture, and so at some point you may not only carry your own genetic sequence around on a thumb drive, but also the sequences of a thousand or so of the more important bacteria you carry in your gut and elsewhere. As I've been looking at the models for genomic data sets that will be gathered in the next five years, the microbiome will likely play an important role.
The various microbiome sequencing efforts look to have sequenced about a 1000 strains so far. I don't yet know what the size of these data sets are.