1. Dirt is Good For Kids Chicago Tribune March 24 th, 2010 By Robert Channick, Special to the Tribune Presented by: Daniel Ma Chakrya San

2. Dirt is Good For Kids… Playing in, and even eating, dirt helps develop immune system, report says 1700 children in Philippines followed from birth to 21 years old Measured C-reactive protein (CRP), a predictive biomarker of cardiovascular heart disease and stroke. CRP level rises during acute inflammation. kids who had more diarrhea and higher levels of exposure to animal feces as an infant — those individuals had lower levels of CRP a healthy dose of germs and pathogens during infancy reduced cardiovascular inflammation in adulthood — a precursor to heart attacks and strokes The study is independent of socioeconomic status, measures of current body fat and other health behaviors This is the first study linking Hygiene Hypothesis to heart disease

3. Hygiene Hypothesis Insufficient stimulation by microbes early in life will lead to more allergy and inflammation. (Strachan, 1989) The Germless Theory of Allergic Disease. Nature Review, Immunology, Volume 1, 2001 pg 9

4. Hygiene Hypothesis Some support for Hygiene Hypothesis: Type I diabetes due to autoimmune defects in non-obese diabetic mice can be prevented by virus infection in mice (Oldstone, 1988) Exposure to at least one course of antibiotics in the first year of life appears to be a risk factor for the development of childhood asthma (Marra, 2006) Staphylococcal lipoteichoic acid inhibits skin inflammation by acting on keratinocytes (Lai, 2009).

5. Hygiene Hypothesis Critiques of the Hygiene Hypothesis The hygiene hypothesis originated not from observations about infection, but from data suggesting a relationship between atopy, family size and birth order (Bloomfield, et al., 2006) Correlation does not imply causation Asthma cases among inner city children were no less frequent than children in more affluent and hygienic communities (Platts-Mill, 1998) Some airborne viruses induce or intensify asthma introducing a confounding variable (Folkerts, et al., 1998) Proponents of the hypothesis suggests renaming it (e.g., the ‘microbial exposure’ hypothesis, or ‘microbial deprivation’ hypothesis) to minimize focus on hygiene and focus attention on impact of microbes on atopic diseases (Bjorksten, 2004)

6. Questions?