99th Dahlem Conference on Infection, Inflammation and Chronic Inflammatory Disorders: Lifestyle changes affecting the host–environment interface

In industrialized nations and high-income regions of the world, the decline of infectious diseases is paralleled by an increase in allergic, autoimmune and chronic inflammatory diseases (AACID). Changes in lifestyle in westernized societies, which impact individually and collectively on intestinal microbiota, may – at least in part – account for the AACID pandemic. Many disease genes that contribute to AACID encode pattern recognition and signalling molecules in barrier-associated cells. Interactions between gene products and environmental factors depend highly upon the host's state of maturation, the composition of the skin and gut microflora, and exposure to pollutants, antibiotics and nutrients. Inflammatory stress responses, if regulated appropriately, ensure immunity, health and relative longevity; when they are dysregulated, they can no longer be terminated appropriately and thus precipitate AACID. The 99th Dahlem Conference brought together experts of various disciplines (genetics, evolution biology, molecular biology, structural biology, cell biology, immunology, microbiology, nutrition science, epidemiology and clinical medicine) to discuss the multi-faceted relationships between infection, immunity and inflammation in barrier organs and the development of AACID. In Clinical and Experimental Immunology we are presenting a compilation of background papers that formed the basis of discussions. Controversial viewpoints and gaps in current knowledge were examined and new concepts for prevention and treatment of CID were formulated.