Man and microbes: an (almost) perfect symbiosis

The 2009-2010 lectures ran from late November to late January. The title of this session was: Man and microbes, an (almost) perfect symbiosis. It followed on from a 2008-2009 session presenting a generic overview of the major mechanisms of interaction between microbes and man, with particular emphasis on the genetic and molecular definition of pathogenic microorganisms and the molecular mechanisms of infectious diseases. This new session therefore focused on the interaction of commensal flora, the microbiota, in particular the intestinal microbiota, and explored the multiple aspects of a human-microbe symbiosis leading to homeostasis and tolerance, the genetic, molecular and cellular analysis of which is becoming one of the great challenges of microbiology. This field, and in particular the disruption of the human-microbiota balance, is opening up a whole new area of medicine, covering inflammatory bowel diseases, obesity, diabetes and certain aspects of atherosclerosis, as well as certain cancers such as colon cancer. It's a safe bet that knowledge of the complexity of the flora that colonize us will eventually lead to a better understanding and control of these diseases. Hence the "almost" in the title of this year's session.