Intended for healthcare professionals

Views & Reviews Personal View

The “hygiene hypothesis” for allergic disease is a misnomer

BMJ 2014; 349 doi: (Published 26 August 2014) Cite this as: BMJ 2014;349:g5267
  1. William Parker, associate professor, Department of Surgery, Duke University Medical Center, Box 2605, Durham, NC 27710, USA
  1. William.Parker{at}

“Biome depletion” is a better term for how immune function is undermined in industrialized societies, writes William Parker, 25 years after The BMJ published David Strachan’s seminal hypothesis

A publication by David Strachan in The BMJ in 1989 described the idea that a loss of species diversity from the ecosystem of the human body could lead to allergic disease.1 Subsequent studies have focused on exactly which species of symbionts might be important,2 and they have expanded the model beyond allergy to include autoimmune diseases3 and cognitive disorders related to inflammation.4 This view, now confirmed by a vast body of literature as a cornerstone of immunology, is likely to affect the discipline of cancer study in the future.5

Strachan’s view can be accurately described as “biome depletion,” an evolutionary mismatch that works in tandem with other mismatches (for example, inflammatory diets and vitamin D deficiency) to undermine immune function in industrialized societies.6 Strachan articulated his quantum leap of thinking in his 1989 paper, stating, “These observations do …

View Full Text

Log in

Log in through your institution


* For online subscription