Here's another report supporting the hygiene hypothesis, suggesting that early-life exposure to certain indoor fungal components (molecules) can help build stronger immune systems, and may protect against future allergies.

The UC team found that infants who were exposed to high levels of indoor fungal components-known as fungal glucans-were nearly three times less likely to wheeze compared with infants exposed to low levels.

Thus, they recommend to avoid overusing antibacterial sprays and soaps to clean their bodies and homes. To avoid being too clean, in other words. Apparently, early-life exposure to common microbial components-like bacterial endotoxins and fungal glucans-can stimulate the body's immune system to produce infection- and allergy-fighting substances.