Microbiomics: 100 Trillion Little Friends?


Trillions of organisms live in and on each human being, making up 90% of the cells in a human body, and some estimate that the typical person carries two to six pounds of bacteria. Commonly viewed as parasites or invaders in the past, they are increasingly seen as crucial determiners of health and disease, central to many basic functions.

Study of the microbiome—the collection of microbes living on humans—has expanded rapidly over the last 15 years. With rising media coverage, popular awareness of the concept is spreading, and reaching the level of mainstream products, with probiotic foods the most prominent examples. This is likely just the beginning, as the field promises breakthroughs in health, and is likely to shift thinking in that area and beyond.


  • Microbiome. The organisms that live in and on humans; mostly bacteria but also viruses and fungi. Also called microbiota. “Microbiome” is also used to describe the collective genomes of these organisms.
  • Microbiomics. The study of the microbiome, including these organisms’ genetics.
  • Pharmacomicrobiomics. The relationship of the microbiome to drug effects and toxicity.
  • Mutualists. Organisms that benefit from living on or in humans, and that help humans in the process.
  • Commensals. Largely harmless “freeloader” organisms.


  • Microbiomics is advancing rapidly but is still in its early stages.
  • The microbiome may play a role in a variety of medical conditions.
  • Microbiomics might change medical care significantly, and could also affect areas such as food and hygiene products.


Microbiomics is being driven by the accelerating pace of basic science in the area, and by spreading interest among scientists, policymakers, and the general public.

  • Advancing science. Scientific attention to the microbiome has greatly increased over the last decade.
  • Inexpensive genomics. The rapidly falling cost of genetic sequencing has enabled the field of microbiomics. It makes it possible to fully sequence the microorganisms involved, and to study the colonies present in individual people.
  • Rising consumer interest. Increasing coverage in mainstream media is driving awareness of the microbiome among consumers.


  • The cutting-edge nature of microbiomics means that it will generate opportunity on one hand—including potentially large- scale opportunities—while simultaneously requiring substantial tolerance for uncertainty about results, market sizes, consumer acceptance, etc.
  • Different population segments and cultures are likely to have distinctly different responses to microbiomic concepts and the products that result from them. This will require exploration of consumer attitudes in a sophisticated way.
  • Companies operating in this area will find an environment full of pseudoscience and dubious claims that is likely to grow more vigorous as products proliferate and consumer awareness rises. This will make many consumers skeptical of all microbiomic products, but might increase the rewards for products found to be based on genuine scientific results.