What is the Hologenome?

New scientific findings indicate the necessity of a revision of our understanding of a complex creature. Until recently, an organism was considered as a singular entity loosely associated with   various individual microbes. However, current research reveals that all complex creatures are a combination of innate and microbial cells as a vast collaborative, co-dependent and competitive network of interlinked ecologies…… a microcosm within.   The extent of this collaboration is so extensive that the volume of microbial cells within and on an organism outnumbers its innate cells by a factor of 10 to 1. Further, the amount of microbial genetic material overwhelms  intrinsic cellular DNA by a factor of 100 to 1. This degree of interdependence requires a new vision of an organism….. neither ‘host’ nor ‘symbiont’ but essential constituents of a ‘holobiont’ as a hologenome.  ‘The hologenome’ references the overarching concept of  the totality of all the holobionts that constitute the biologic system on our planet

Importance of the Microbiome

A microbiome is the entirety of the microbial life that is a part of the ecological communities comprising all complex creatures. For example, the bacterial colonization of the intestine that begins at birth is a process of considerable interest to science and medicine. Numerous studies have shown that there are differences between the gut microbiota of babies born transvaginally and are therefore exposed to maternal vaginal bacteria compared with those born via Caesarean section. In the latter instance, neonate gut microbiota bacteria is less diverse during the first months of life. Now, a new study has analysed the evolution of the gut microbiota of low-birth weight infants and premature babies. This research has identified that immediately after birth the mouth microbiota is similar to that of the gut in these babies, but that it differs substantially after three weeks of  life. The study, published in the latest edition of the American Academy of Microbiology journal ‘mBio’, is the first to analyse the time dependent differentiation of the exact composition of the microbiota in varying body sites of newborn infants. http://mbio.asm.org/content/4/6/e00782-13 Important implications include the differing susceptibility of low birth weight newborns to necrotizing enterocolitis compared to normal birth weight newborns.