In the fight against disease, we're vastly outnumbered. The number of bacterial cells and their genetic material far outnumber human cells and genes. Take the digestive tract as an example. In the lower digestive tract (commonly called the gut), there are about 10 times as many bacterial cells as there are human cells. The genetic diversity in the gut is even greater: Bacterial DNA accounts for 100 times as many genes as human DNA.
What's more, we're beginning to appreciate that many of these bacteria actually are friendlies in the fight. And we rely on them to digest food, train our immune systems, stave off infection, and more. They're so important, in fact, that we would be hard pressed to survive without them.
The bacteria colonize our bodies with diverse and complex ecosystems that, like any ecosystem, thrive when balanced and flounder when thrown out of whack. (The term for this is dysbiosis.) And so, rather than treat all bacteria as icky bugs to be sanitized and destroyed, we're looking at ways to keep these populations in balance and keep our patients and we know that bacteria play an important role in maintaining health. When this population of bacteria is disrupted, it can lead to serious health problems.
Nicholas Chia, Ph.D. discusses the advances in the Center for Individualized Medicine, and the studies being done of the human Microbiome. With recent advances, treatments such as the fecal transplant for treating C. Difficile, have been made possible.