Without infections your immune system gets bored and starts attacking you. You need to have something for your immune system to do on a regular basis. Toxo is to a very large degree asymptomatic. You are full of and covered with organisms. Being paranoid about infection isn't helpful to anyone. Ok you don't like cats, that's fine, but are you as passionate about rare steak which is a much more common vector?
Malaria... is not asymptomatic.
You will have plenty of exposure to microbes simply by existing outside of a sealed sterile chamber, and microbes != pathogens. There's no need to encourage exposure to and infection by pathogens, and this idea often results in increased risk or severity of disease. See: "chickenpox party" intentional exposure of children to varicella, putting them at risk of shingles as adults, with the risk increasing the younger they are at the time of infection.
https://en.wikipedia.org/wiki/Hygiene_hypothesis?useskin=vec...