07 Jul Allergens in the Home
The past three decades has seen a dramatic increase in the prevalence of allergic diseases like asthma, eczema, hayfever and food allergies in western countries. Health statistics reveal a disturbing story: peanut allergies has more than doubled in the past 5 years, 1 in 3 children will experience allergies by the age of 5, and hospital admissions for anaphylaxis (a potentially life threatening allergic reaction) has increased by 700% (Bijlsma, 2018). Environmental factors are likely to play a major role: including our mode of birth (caesarean), diet (breast milk and consumption of fermented foods) and drugs (antibiotics), however your home could also be affecting your risk for developing asthma and allergies.
A recent study compared the microbiomes of indoor dust levels in the homes of Amish versus Hutterite farm children whose genetic ancestry and lifestyles are similar (Stein et al, 2016). They discovered significantly higher levels of bacteria and endotoxins in the Amish households whose children have very low rates of asthma and allergies (compared to Hutterite children) and this was thought to be due to their exposure to farm animals. Interestingly however, unlike the Amish, the Hutterites employ highly industrialised farming practices involving the use of chemical pesticides (most pesticides are antibacterials). The idea that microbial exposures in household dust may influence the composition of an infant’s gut microbiome is quite plausible given that an infant’s breathing zone is close to the floor and they ingest up to 8 times more dirt than the average adult. This is why you should not use chemical cleaners to dust the home!