SignificanceOur results show that a standardized laboratory psychosocial stressor causes a greater inflammatory response in young healthy participants with an urban upbringing in the absence of pets, relative to young healthy participants with a rural upbringing in the presence of farm animals. In view of the known links between persistent inflammatory states and psychiatric disturbances, and considering that many stress-associated physical and mental disorders are more prevalent in environments offering a narrow range of microbial exposures, we feel that our findings are of general interest and significance. Moreover, we feel our study is timely, as urbanization and the associated socioeconomic consequences are increasing.

No abstract