New research suggests that changes to the bacteria that live inside all of us are responsible for the increasing number of people with allergies.
Horizon investigates this claim by conducting a unique experiment with two families with allergies, in order to find out just what it is in the modern world that is to blame.
With a raft of mini cameras, GPS units and the very latest gene-sequencing technology, this documentary discovers how the western lifestyle is impacting their bacteria.
Why are these changes making us allergic? And what can we done to put a stop to the allergy epidemic?
Allergies: Modern Life and Me airs 7.30pm, Monday 7 September on SBS.