There have been many studies that have started with the theory that exposure to more environmental allergens leads to an immune system that is less sensitive to common proteins like pollen, dander, etc. This is significant for allergy and asthma sufferers since, in theory, it would lead to less sensitivity and less instances of allergic reaction.
_A recent study, led by scientists at the University of Bristol School of Veterinary Sciences, has found that test subjects raised, particularly during early life, in a farm environment had increased levels of regulatory T-lymphocytes (T-cells). This is critical in that the regulatory T-cells dampen immune cells responses, which can lead to reduced allergic reactions to every day proteins and allergens.
_In this study, researchers separated two sets of piglets (they chose piglets because of their close physiologically similiarities to humans). The first set was allowed to be nursed by their mother under normal farm conditions. The second set was raised in an isolated, more hygienic environment and fed formula milk, more similar to the rearing of human infants.
_What they found was that the piglets in the more hygienic environment had lower levels of the regulatory T-lymphocytes. This means they are more likely to have an immune response and inflammation when they come in contact with every day triggers. Other studies have shown that a reduction in regulatory T-cells has been linked to the development of allergies and autoimmune diseases.
_Similarly, this study also found that the farm raised piglets had lower antibody responses when they were transitioned from milk to solid food. A lower antibody response such as this can mean that they are less likely to suffer any sort of reaction when new, solid foods are introduced into their diets.
_While the study is still only one piece of the puzzle, it does suggest two things. First, during early development, environmental factors can shape an immune system into one that is hypersensitive to common protein allergens or one that ignores these triggers. Secondly, it leans toward the idea that the environment can also play a major role in the development of food allergies or intolerances.