Mechanism for impaired allergic inflammation in infants may explain hygiene hypothesis: The hygiene hypothesis says increased sanitation in industrialized countries has led to increases in asthma

New research describes a mechanism in a mouse model of asthma that supports the hygiene hypothesis -- researchers found that infant mice need a higher exposure to a bacterial endotoxin, compared to adult mice, to avoid developing asthma-like reactions to house dust mites. The hygiene hypothesis suggests that decreased exposure to microbial products in industrialized nations is the main driver of increased allergic airway disease.