The skin microbiota forms the body’s first line of defense against pathogens and external threats. Changes in environmental exposures can drive bacterial dysbiosis, a condition in which the overall makeup of the skin microbiota is altered. Bacterial dysbiosis is associated with allergies and sensitivities. A new study suggests that exposure to Acinetobacter bacteria early in life provides protection against inflammatory disorders and allergies. Acinetobacter bacteria are ubiquitous in the environment and are commonly found in soil.

The study was conducted among 180 children living in Karelia, a region that straddles the geopolitical borders of Finland and Russia. Whereas the Finnish side of Karelia is modernized, the Russian side has maintained a traditional lifestyle that involves farming and animal work. The children from the two regions were examined for symptoms of allergies and sensitivities to common allergens when they were between the ages of 7 and 11 years and again when they were between the ages of 15 and 20 years. Samples of the children’s skin and nasal microbiota were collected for analysis.

The prevalence of allergies and allergen sensitivities was 3 to 10-fold higher among Finnish children, compared to Russian children. In addition, Russian children rarely exhibited hay fever or peanut sensitivity. Generally, these findings were replicated at the 10-year follow-up examination. The children’s skin and nasal microbiota demonstrated notable differences. In particular, the Russian children’s microbiota had a diverse, abundant population of Acinetobacter bacteria. These findings suggest that early life exposures modulate the risk of developing allergies and allergen sensitivities later in life.

• Link to study abstract.