Well its microscopic and it lives in a variety of places. For instance, it lives on our skin and so you could potentially do skin samples and put in petri dish…
And then it lives in our mucousal membranes. You can’t really inspect these areas.
And our colon is another place…but there’s so much junk in there that its likely hard to seperate from other matter.
It lives at the microscopic level so you shouldn’t be able to visually see it in most cases.