Are we too clean for our own good? Did our paranoia about “germs” and cleanliness put us at a disadvantage?
The hygiene hypothesis states “the lack of early exposure to infectious agents, symbiotic microbes and parasites increases susceptibility to allergic diseases by suppressing the natural development of the immune system”. It has also been called the “lost friends theory”. Without the microbial friends that we evolved with, our immune systems can’t respond to stimuli appropriately.
Basically, the Hygiene Hypothesis suggests that you shouldn’t be too sterile in your daily life. It is important to be exposed to potential partners and potential threats in order for the immune system to learn the appropriate immune response. This is especially important in children, and even more so in children under the age of 3. We need to relax a bit and let our children play in the dirt every now and then.