Bacterial Exposures and Associations with Atopy and @entity565 in XXXX .

@entity1 @entity565 @entity402 @entity66
BACKGROUND: The increase in prevalence of @entity565 and @entity66 in Western countries has been linked to aspects of microbial exposure patterns of @entity1 . It remains unclear which microbial aspects contribute to the protective farm effect. OBJECTIVE: The objective of this study was to identify bacterial groups associated with prevalence of @entity565 and @entity402 , and to quantify indoor exposure to some of these bacterial groups. METHODS: A DNA fingerprinting technique, denaturing gradient gel electrophoresis (DGGE), was applied to mattress dust samples of farm @entity1 and control @entity1 in the context of the GABRIEL Advanced study. Associations between signals in DGGE and @entity402 , @entity565 and other allergic health outcomes were analyzed. Quantitative DNA based assays (qPCR) for four bacterial groups were applied on the dust samples to seek quantitative confirmation of associations indicated in DNA fingerprinting. RESULTS: Several statistically significant associations between individual bacterial signals and also bacterial diversity in DGGE and health outcomes in @entity1 were observed. The majority of these associations showed inverse relationships with @entity402 , less so with @entity565 . Also, in a subsequent confirmation study using a quantitative method (qPCR), higher mattress levels of specifically targeted bacterial groups - Mycobacterium spp., Bifidobacteriaceae spp. and two different clusters of Clostridium spp. - were associated with a lower prevalence of @entity402 . CONCLUSION: DNA fingerprinting proved useful in identifying bacterial signals that were associated with @entity402 in particular. These findings were quantitatively confirmed for selected bacterial groups with a second method. High correlations between the different bacterial exposures impede a clear attribution of protective effects to one specific bacterial group. More diverse bacterial flora in mattress dust may link to microbial exposure patterns that protect against development of @entity66 .
