Bacterial Balance Medicine...and the Human Microbiome Project
I was just thinking the other day about how we like to think of ourselves as humans, but we are infact mere living structures for colonies of microbes ;). Apartment complexes with central heating, and food delivery.
OK, there is some basic human structure dependent on DNA passed along from our ancestors, but there is also (by weight) an astonishing percentage of cell sized travelers on our skin, in our bellies, etc...I've read it can be 10% of body weight, and that in terms of cell numbers, there are actually 10x more bacteria than human cells. That means 90% of the cells you are walking around with all the time are not coding proteins from your DNA, but rather microbial proteins.
It is not easy to count all these organisms I imagine, so who knows how much is enough/too little/too much. At the same time, if for one reason or another one of the bacterial groups gains an upperhand, then we end up with systemic problems...
This seems to happen following a course of antibiotics, or other medications, or in persons with some immune system deficiency. I've heard gut flora populations can be harmed following food poisoning, or bouts of diarrhea.
Yeast, candida, overgrowth due to damaged flora populations is a common problem.
Maybe one day there will be a form of medicine that seeks to harmonize the lifecycles of these single celled hitchhikers...I suppose in some form this exists in the science of nutrition...infection perhaps? any others? ...and low and behold, my Google Fu reveals the Human Microbiome Project....
Some links that seem relevant:
Powerpoint from MIT on the Microbiome
NIH site for the Human Microbiome Project