A recent study from Finland suggests that exposure to animals in early childhood may play an important role in the development of a healthy immune system.
The last century, especially the last several decades, has seen a steep rise in levels of allergies, asthma and auto-immune disorders. What is interesting is that statistical analysis shows that typically these conditions are more prevalent in developed nations than in developing countries, and when families migrate from a developing country with a low incidence rate to a developed one with a high incidence rate, it only takes one generation for the conditions to present.
A recent study from the University of Eastern Finland suggests that exposure to farm animals in early childhood may play an important role in the development of a healthy immune system, specifically in regards to the role of dendritic cells and cytokine production. Dendritic cells are messengers that present antigens to other cells to elicit an immunological response. Via this mechanism they regulate cytokine (messenger protein) production, adaptive immune system response, and are essential for the establishment of immunological memory.
Many studies have noted that children who grow up around farm animals are less likely to develop childhood atopic diseases (like asthma and eczema). However, though a clear relationship could be found between growing up on a farm and the development of a healthy immune system, the mechanistic link between the two was unclear. This study attempted to understand the link.
Source: Study Shows Exposure to Animals in Early Childhood Supports Immune Development