These are truly things to remember, because it will be years before these become mainstream tenants of clinical microbiology.

I have found that B. Hominis produces spores in the gut from mature forms that may seem harmless.
But, the spores it would seem, can migrate to the blood stream via monocytes [macrophages] The cells will react as the spore develops, and will eventually self destruct. This causes immunopathology in the host [symptoms] and the parasite may exist for some time in free blood until taken up by other macrophages [hypothetically].
It is also possible, there are small spore-type forms that can transverse the gut wall.
This may work for some fungal forms as well........Shroom