Traditionally what we consider to be “self” is usually restricted to the collection of 10 trillion or so eukaryote cells that derive directly from our own genomes. However, the “omic” technologies of the 21st century are radically redefining this view, so that “self” can now be seen to extend beyond the traditional precinct of our visible form, and to include our resident bacterial community. In fact, these normally invisible cells outnumber what we consider to be our own cells, by a factor of ten and contain at least ten times more DNA than our own genome. Recent studies have suggested that our personal bacterial flora, or microbiome, can influence our predisposition to gain or lose body weight, and even our moods and ability to learn. To explore the issues of identity that these new findings raise, I have taken samples from my own microbiome and cultured them using my own blood. In the growth media that I use, the only source of nutrition for the bacteria is my blood so to grow, they have to partly dissassemble my own chemistry and restructure it into their own cells. The resulting, and extraordinary forms, are derived from both my eurkayotic self and prokaryotic self, and so blur the boundaries of my own identity, and what makes me human.