Human Microbiome Project

Microbes occupy a number of niches on the surface of and inside human body. In fact, in an adult human being, microbe cells outnumber human cells 10 to 1. It makes us a supra-organism or a composite of species. The gut microbiome, for example, consists of at least many thousands of bacteria and archea species many of which can not be cultured. Arrival of fast and economic sequencing techniques e.g. 454 and SOLEXA has made the molecular (16S rRNA based) identification or microbes within the reach of labs. It appears that there is a lot of diversity in a specific niche across humans and other mammals.

NIH Human Microbiome Project is an intitiative to understand this composite of species. Specifically, the aim is to understand whether there is a core group of microbes that all humans share. The second one is to understand whether the composition of microbiota in a specific niche relates to health. For example there is strong evidence to suggest that gut microbiota of obese individuals is different from lean ones. Transfer of gut microbiota from a obese human to a germ free mouse (a humanized mouse) can induce adipocity which can again be transferred to other mice, yet again. Such a finding has far reaching consequences for a population dealing with calorie-rich diet and obesity.