Yeah, you really can't send balloons to space. ;)
Makes sense to me that stratospheric germs would be different. That doesn't make them extraterrestrial.
But it doesn't rule it out, either. If Earth *is* being constantly seeded from space, then it makes sense that the incoming stuff would be similar to what's already here.
The folks behind the research are pushing panspermia theory, and much of this article here is propaganda.
Everybody has an agenda of some sort. This particular idea has been floating around for a long time, but there's a possibility that something concrete will be discovered when we finally get a sample from a comet...
Where are the little bacteria corpses in the moon dust?