Final answer:
The hygiene hypothesis posits an inverse relationship between exposure to pathogens and the incidence of allergies and autoimmune diseases, attributing a decrease in microbial diversity to an increase in inflammatory diseases. This suggests that modern sterile practices in developed countries might hyperactivate the immune system, causing it to overreact to harmless substances.
Step-by-step explanation:
The hygiene hypothesis suggests that due to the modern indoor lifestyle and widespread use of antimicrobial agents, there has been a decrease in the diversity of microbes within the human microbiome.
This lack of microbial exposure is thought to contribute to an increase in inflammatory diseases because the immune system, lacking the challenge of a broad array of pathogens, may inappropriately target the body's own tissues or otherwise harmless substances, leading to allergies and autoimmune diseases.
Exposure to a greater variety of pathogens, particularly in early childhood, is believed to be essential for the proper development of the immune system. Large families, lower usage of antibiotics, and less stringent cleanliness can result in increased microbial exposure, thus potentially lowering the incidence of allergies and autoimmune disorders.
In developed countries, where hygienic practices are pervasive, the immune system may become overly sensitive and hyperreactive, resulting in an uptick of allergies. This could mean that interacting with our microbial environment in a less sterile way might be beneficial for immune system training and regulation.