It can go the other direction, too: exposure to moldy home environments gave me (now resolved) food sensitivities, dust allergies, pet-associated allergies, etc.
You can definitely undertrain, or overwhelm, the immune system if not cautious!
Don't underestimate the amount of cockroach debris present in a modern home. There's a positive correlation between asthma and in-home roach population.
Don't underestimate the amount of cockroach debris present in a modern home. There's a positive correlation between asthma and in-home roach population.