Synthetic fibers haven't been around long from an evolutionary point of view. Are you sure they don't encourage a novel pattern of bacteria growth that could be

Synthetic fibers haven't been around long from an evolutionary point of view. Are you sure they don't encourage a novel pattern of bacteria growth that could be harmful to some humans? Anecdotally, synthetic fibers are known to easily start smelling bad. I often clean things with synthetic microfiber cloths, and I occasionally wash them in diluted bleach, because I noticed they can start to smell bad if I don't.