It is now clear that, for any individual, the risk of developing allergies and other chronic inflammatory diseases (CIDs) depends on many other factors - in addition to microbial exposure.
These include diet (including vitamin D deficiency), pollution, climate change, less physical activity, obesity, socioeconomic factors and stress.
All of these can amplify the immunoregulatory deficit resulting from the changes to our human and microbial environment
Genetic predisposition is also a risk factor.
Why don’t we all suffer from allergies etc?
This may explain why we do not all suffer from these diseases. It is likely that we all still get some of the microbe exposure we need.
Whereas for some people this is sufficient, for others it is not.
In these individuals, allergies and other CIDs may be triggered, when one or more of the other factors cause further dysregulation of the immune system.