Scientific rationale

The human microbiome consists of the genetic material contained in the 10-100 trillion microbial cells living symbiotically within and on each person, primarily made up of bacteria in the gut (ref 1). The composition of microbes both within and between different individuals varies significantly, and is known to be influenced of key biotic and abiotic factors.

The human gut microbiome in particular is a rapidly expanding area of research, particularly as sequencing methods and analytical techniques develop. Great progress has been made in terms of characterising the structure and composition of the human microbiome (ref 2), evidence showing the great importance of diet in microbial species diversity (ref 3).

In turn, the gut microbiome plays a significant role in a number of host processes throughout the life course, fundamentally affecting health through impacts across nutrition, physiology and immunity. In particular, studies show a significant link between the microbiome, digestion, and metabolism, playing a substantial role in weight and nutritional health (ref 4).

This work suggests that harnessing the microbiome could provide new and highly effective routes to improving health outcomes; however more research is needed to fully understand microbiome functionality and how it can be influenced. Human-microbiome interactions are highly complex and there are still significant questions regarding the composition of microbes required for good health, microbiome mechanisms of action, the role of the microbiome in reducing overweight and obesity, the food stuffs that promote an appropriate diversity of gut microbes, and the impact of increasing homogenisation of global diets.


  1. L.K. Ursell et al. (2012) Nutr Rev. 70(1): 38–44. doi:10.1111/j.1753-4887.2012.00493.x.
  2. NIH Human Microbiome Project.
  3. David, L.A. et al. (2014) Nature. 505: 559–563. doi:10.1038/nature12820.
  4. John, G.K and Mullin, G.E. (2016) Curr Oncol Rep. 18(7):45. doi: 10.1007/s11912-016-0528-7.