Slowly but surely, the hygiene hypothesis is going to be more and more perforated. A new NEJM paper finds

Hypopharyngeal samples were cultured from 321 neonates at 1 month of age. Twenty-one percent of the infants were colonized with S. pneumoniae, M. catarrhalis, H. influenzae, or a combination of these organisms; colonization with one or more of these organisms, …, was significantly associated with persistent wheeze (hazard ratio, 2.40; 95% confidence interval [CI], 1.45 to 3.99), …, and hospitalization for wheeze (hazard ratio, 3.85; 95% CI, 1.90 to 7.79).

The editorial writes

bacterial colonization of the [throat] in the first four weeks of life indicates a defective innate immune response very early in life, which promotes the development of asthma.

Accepting this view requires only a small further step to the responsible environmental trigger.

BTW I will detail the vitamin D studies on the next meeting of the American Academy of Allergy, Asthma and Immunology 2008 in session # 330 – come and visit us at Sunday March 16, 2008, 10:45 in Philadelphia at the Pennsylvania Convention Center.