the changing microbial environment and chronic inflammatory disorders微生物环境的变化和慢性炎症性疾病.pdf

ORIGINAL ARTICLE The Changing Microbial Environment and Chronic Inflammatory Disorders Graham A.W. Rook, BA, MB, BChir, MD There is much to be gained from examining human diseases within the expanding framework of Darwinian medicine. This is particularly true of those conditions that change in frequency as populations develop from the human ‘‘environment of evolutionary adaptedness’’ to the living conditions of the rich industrialized countries. This development entails major changes in lifestyle, leading to reductions in contact with environmental microorganisms and helminths that have evolved a physiologic role as drivers of immunoregulatory circuits. It is suggested that a deficit in immunoregulation in rich countries is contributing not only to increases in the incidence of allergic disorders but also to increases in other chronic inflammatory conditions that are exacerbated by a failure to terminate inappropriate inflammatory reponses. These include autoimmunity, neuroinflammatory disorders, atherosclerosis, depression associated with raised inflammatory cytokines, and some cancers. n 1989, Strachan showed that in young adults, a history framework of ‘‘evolutionary medicine,’’ which seeks to I of hay fever was inversely related to the number of clarify our understanding of disease by considering our children in the family when the subject was 11-years old.1 evolutionary history. Further studies suggested that having many siblings, This review first outlines various ‘‘failed’’ versions of especially older ones, correlated with diminished risk of the hygiene hypothesis and then describes the old friends hay fever, and these findings were considered consistent