An interesting analogy, but the wild variety of gut flora makes me think that our borders are not so closed. Our own homogenous cells are outnumbered (some stud

An interesting analogy, but the wild variety of gut flora makes me think that our borders are not so closed. Our own homogenous cells are outnumbered (some studies say 10 to 1) [1] and dependent [2] on our vast colonies of bacteria. [1]: https://en.wikipedia.org/wiki/Human_microbiome https://en.wikipedia.org/wiki/Human_microbiome [2]: http://www.nytimes.com/2010/07/13/science/13micro.html?pagewanted=all http://www.nytimes.com/2010/07/13/science/13micro.html?pagew...