Man has moved rapidly from the hunter-gatherer environment to the living
conditions of the rich industrialised countries. The hygiene hypothesis
suggests that the resulting changed and reduced pattern of exposure to
micro-organisms has led to disordered regulation of the immune system,
and hence to increases in certain chronic inflammatory disorders. The
concept began with the allergic disorders, but there are now good
reasons for extending it to autoimmunity, inflammatory bowel disease,
atherosclerosis, depression associated with raised inflammatory
cytokines, some cancers and perhaps neuroinflammatory disorders such as
Alzheimer's and Parkinson's. This book discusses the evidence for and
against in the context of Darwinian medicine, which uses knowledge of
evolution to cast light on human diseases. It is the first book to
consider the broader implications of the hygiene hypothesis in areas of
medicine where it has not previously been applied. The approach is
interdisciplinary, looking at man's microbiological history, at the
biology of the effects of microorganisms on the immune system, and at
the implications for chronic inflammatory disorders in multiple organ
systems. Finally, the authors describe progress in the exploitation of
microorganisms or their components as novel prophylactics and treatments
in several branches of medicine.
