At the risk of loosing our inner geeks, I’m wondering whether a decrease in pore size from .2 microns to .1 micron makes any practical difference for backpackers?

I realize that a smaller pore size means smaller gazigglies get filtered out. What I’m wondering is whether there are any significant numbers or types of harmful stuff that would make it through a .2 micron filter that a .1 micron filter would stop.