Last night I went into Boston to hear my potential future son-in-law – or perhaps I should say my current ‘son-in-law,’ Kevin, give a talk at Harvard Med School. He’s a graduate student in immunology as was speaking as part of a series by a student run organization called ‘Science in the News.’ The topic last night was explaining some of how microbes (bacteria) function in our bodies.
My body contains more bacteria than the number of people on earth. Though if you scraped them off my skin and collected them from all the surfaces within and without of me, their total mass would amount to only about five pounds, they outnumber the actual cells of my body. The densest concentration of these microbes is in my large intestine. This is where, I learned, food stays for an average of three days as these microbes work to break down what the rest of my digestive system couldn’t. There are so many different microbes that have such interdependent functioning in the large intestine that we don’t even know all of what is there. Many of these microbes are essential to our well-being where they are, but could kill us if they travel to other parts of the body. Some are so secretive that even scientists in their white lab coats can't culture them outside the body.
I’m fascinated by all these parts of me that aren’t me. These microbes are like independent contractors that have their own agenda. I can’t order them around and I can’t survive without them. On the bright side, I am the whole world to them. But on the down side, I am just a food source, just a place to live. As long as the nutrients keep on coming and I stay away from powerful anti-biotics, they are content to go about their microbial way and I should be grateful.
So this morning as I go put the trash out, I have just a little more respect for the miracle of my large intestine – ‘the densest concentration of microbial variety on earth.’ I think I’ll start eating yogurt regularly as my way of saying thank you to all my unknown friends and allies down there.
(for more fascinating microbial information and links to the talks – visit Kevin’s blog http://scienceblogs.com/webeasties )