161 - ‘A dynamic partnership : Celebrating our gut flora’. Anaerobe. Volume 11, Issue 5, 247-251

Among body sites normally sporting a community of microbes, the human gut, predominately the colon, harbors the greatest number and diversity of organisms, primarily bacteria. Pasteur with prescient insight postulated that our health is intertwined with our resident flora. Dr. Joshua Lederberg, a Nobel Laureate (1958) at the age of 33, later coined the term ‘microbiome’ or the collective genome of our indigenous microbes and further proposed that a comprehensive view of human genetics and physiology is a composite of human and microbial genetics. Later, the human genome project revealed 233 proteins with homologues only in bacteria, suggesting that we have acquired these genes from our resident flora. This has led to a fundamental question-namely, to what extent is human life dependent on its microflora? Investigations addressing this question have spawned two new scientific disciplines. The first titled ‘Eco-Devo’ or ecological developmental biology pursues the hypothesis that human development is both hardwired in our genes and derived from our interactions with microbes. The second field, cellular microbiology, is built on the principle that studies of normal flora as well as microbial pathogens provide new insights into host cell biology, biochemistry and development. The goal of this paper is to provide a perspective on recent data supporting the hypothesis that the relationship between the host and the gut flora is not simply commensal (i.e.living together without injury to either partner) but rather symbiotic or mutualistic; namely, an interdependent relationship essential to our well-being.