Typically we think of biomes as large communities of organisms covering vast areas; but a new idea of microbiome is becoming popularized as our understanding of microorganisms grows. The human body is just such a microbiome. For every one human cell in the body there are 10 microbial cells! If that sounds like disportionate amount and you find yourself wondering how it is possible to have more microbial cells than human cells, consider the fact that a typical microbe cell is much smaller than a human cell and can fit in between the spaces of human cells. In a 200 pound adult, it roughly amounts to 2-6 pounds.
These microbes are mostly bacterial, many of which are critical to the body’s healthy growth and function. Bacteria live inside our digestive system and help our bodies digest nutrients and synthesize vitamins. Many also help our immune systems fight disease or even other harmful bacteria. In return these bacteria receive their own small share of nutrients. Like it or not, our bodies are ecosystems complete with niches that other organisms compete for.
Researchers participating in the huge collaborative effort, called the Human Microbiome Project, have sought to survey the human microbiome for the first time. New technological advancements have enabled researchers to sequence the genomes of microbes in the human body. Not a simple task considering there are approximately 10,000 different species. Their purpose for doing this goes beyond simply identification for its own sake. Researchers first focused on studying healthy individuals so they would be able to define what a healthy human microbiome should look like in terms of diversity. This also allows researchers to start asking questions about unhealthy microbiomes, and how these relate to health generally. The findings of the Human Microbiome Project are only at the tip of the iceberg in understanding humans as a microbiome but serves as an important initial step for future research.
For a more in depth reading about the Human Microbiome Project check out the source publication by National Institute for Health