Biodiversity loss can trigger rising allergy levels

Helsinki: Loss of biodiversity could trigger rising allergy levels among millions of urban dwellers worldwide, which includes greater incidence of asthma, allergies and other chronic inflammatory diseases, says a Finnish study.

Emerging evidence indicates that commensal (harmless) microbes inhabiting the skin, airway, and gut protect against inflammatory disorders. However, little is known about the environmental determinants of the microbiome (totality of microbes).

Ilkka Hanski, bioscientist from University of Helsinki, investigated whether reduced human contact with nature and biodiversity influences the composition of skin bugs and allergen sensitivity in a random sample of 118 teenagers, the journal, Publication of the National Academy of Sciences reports.

The authors found that subjects living on farms or near forests had more diverse bacteria on their skin and lower allergen sensitivity than individuals living in areas with less environmental biodiversity, such as urban areas or near bodies of water, according to a Helsinki statement.

Furthermore, allergen-sensitive individuals had lower diversity of one class of bacteria, gammaproteobacteria, on their skin than healthy study subjects.

The presence of one gammaproteobacterial member, Acinetobacter, was tied to the expression of the anti-inflammatory marker IL-10 in the blood of healthy study subjects.

The findings suggest that the increasing prevalence of inflammatory diseases may be linked with the changing biodiversity of the environment and commensal skin bacteria.