What Is The Human Microbiome?

For centuries humans have co-evolved with their microbiome: trillions of microbes – bacteria, fungi, archaea and viruses – that live in our gut, on our skin and elsewhere in our bodies. In fact, the human body harbors at least as many bacterial cells as human cells; over 100 trillion bacteria, representing thousands of different species. Even more importantly, these bacteria have several hundred times more genomic potential (genes) than the human genome. This genetic repertoire allows the microbiome to perform a myriad of essential functions.

The human microbiome is now one of the fastest growing areas of biology, and is considered by many to be a “newly discovered organ” with the potential to have an overwhelming impact on human health. This organ – the ‘microbiome’ – performs diverse functions that are critical to our health including immune system development and homeostasis, synthesizing nutrients such as vitamins and hormones, metabolizing drugs and harvesting energy from our diet. Detrimental changes to the human microbiome, also known as dysbiosis, have been implicated as a key factor in allergies, arthritis, asthma, autism, colon cancer, C. difficile infections, diabetes, inflammatory bowel disease, obesity and many other diseases.

Other Microbiomes

Like humans, virtually all other animals and plants have distinct microbiomes, which perform functions essential to their hosts. Similarly, physical environments such as soils and the oceans have microbiomes. Environmental microbiomes perform critical functions such as primary production (e.g., photosynthesis), nutrient cycling, decomposition and degradation of toxic chemicals.

Why Are Microbiomes Important?

We are witnessing a revolution driven by microbiome research, which could lead to some of the most important scientific advances of our time in not only medicine, but a variety of other fields. These advances offer tremendous potential for medical, environmental and economic benefits. Understanding the microbiome may enable early diagnosis of diseases, and manipulation of the microbiome may enable prevention or curing of diseases. Understanding and managing environmental microbiomes may improve productivity and sustainability of agriculture and diverse resource industries, such as forestry, mining and aquaculture.