The hygiene hypothesis contends that fewer opportunities for infections and microbial exposures have resulted in more widespread asthma and atopic disease.
The hygiene hypothesis lays groundwork for our understanding of how altered microbial exposures can drive atopy; yet since its introduction increasing evidence suggests the exposure of our immune system to the intestinal microbiota plays a key role in development of atopic disease.
Relevant microbial exposures may include gastrointestinal biota.
Microbial exposures have been suggested to confer protection from allergic disorders and reduced exposures to gastrointestinal microbiota have been proposed as an explanation for the increase in asthma prevalence.
The hygiene hypothesis suggests that a lack of microbial exposures during the crucial stages of immune maturation in infancy, results in immune modulation (Th2-biased response) that increases susceptibility to development of allergic disease [17].
Adverse microbial exposures might contribute to diabetogenesis.
The presumed mechanism is reduction of unspecified microbial exposures.
However, few studies have evaluated microbial exposures among WWTP workers.
Few studies have evaluated the relation of home characteristics to measures of multiple microbial exposures.
Cohort-specific associations between the indoor microbial exposures and FeNO were evaluated using multivariable regression analyses.
Only few studies measured early-life microbial exposures and investigated health effects prospectively.
