Let’s talk about science: The human microbiome – Pittsburgh Post-Gazette

Most people learned in school that the human body, like all living organisms, is made of cells. We have about 7 billion heart cells, 100 billion brain cells and 25 trillion red blood cells. All said and done, our bodies are made of about 37 trillion cells. Thats a mind-boggling number, but thats not the whole story. Our bodies are not our own up to 40 trillion bacteria and other microbes call us home. This collection of microscopic life that exists within and on us is called the human microbiome.

Our microbiome is an example of symbiosis, or a close association between two different species. There are three main types of symbiosis: mutualistic (both species benefit), commensal (one species benefits, no effect on the other) or parasitic (one species benefits, the other is harmed). The vast majority of our microbiome is commensal, but some species are mutualistic. Your large intestine is home to most of your microbiome up to 1,000 species of bacteria. These bacteria feast on food that our bodies cannot digest, transforming that food into chemicals we can use. Your gut bacteria can also prevent harmful bacteria, such as C. difficile, from invading your colon.

Bacterial diseases are treated with antibiotics that kill the infecting bacteria, but they can also kill the bacteria in your gut. This can cause C. difficile colitis, or inflammation of the large intestine accompanied by diarrhea. In extreme cases, C. difficile colitis may require hospitalization. There is evidence to suggest that transplanting bacteria from the stool of a healthy donor can keep the C. difficile in check. These stool transplants are gaining acceptance in the medical field as C. difficile gains resistance to antibiotics.

Its easy to live your life without ever thinking about your microbiome. Most people never give it a second thought. But the more we explore and understand it, the better we will understand being human is more than being human.

Read more:
Let's talk about science: The human microbiome - Pittsburgh Post-Gazette