Context: The hygiene hypothesis attempts to explain the increased rates of asthma worldwide as a direct and unintended result of reduced exposure, during childhood, to non-pathogenic bacteria and viruses. It has been proposed that the reduced exposure to bacteria and viruses is due, in part, to increased cleanliness and decreased family size in modern societies. Exposure to bacterial endotoxin in early childhood may prevent the development of asthma, but exposure at an older age may provoke bronchoconstriction. Evidence supporting the hygiene hypothesis includes lower rates of asthma on farms and in households with pets.

Question: What hypothesis tries to explain the increased amount of asthma world wide?
Answer: The hygiene hypothesis

Question: How does the hygiene hypothesis explain the increase in asthma?
Answer: a direct and unintended result of reduced exposure, during childhood, to non-pathogenic bacteria and viruses

Question: What has caused the reduced exposure in childhood?
Answer: increased cleanliness and decreased family size in modern societies

Question: What could prevent asthma?
Answer: Exposure to bacterial endotoxin in early childhood

Question: What is some of the evidence backing the hygiene hypothesis?
Answer: lower rates of asthma on farms and in households with pets.

Question: What hypothesis explains the increased rates of viruses worldwide?
Answer: Unanswerable

Question: How does the hygene hypothesis explain the cause of bronchoconstriction?
Answer: Unanswerable

Question: What can cause bacteria in pets?
Answer: Unanswerable

Question: Why are people less likely to want to live on a farm?
Answer: Unanswerable

Question: What is some evidence used to support the hypothesis on non-pathogenic bacteria?
Answer: Unanswerable