By Ronnie Childs, RRNA Member and speaker at August 1st, 2013 meeting “Two Ecosystems”
I’m a far cry from a scientist, but science is one of my favorite topics in which to indulge my bookworm tendencies. One topic I’ve been coming across over and over recently is the human microbiome, which is a fairly new term—my Spell-Check just jumped on it, in fact. It refers collectively to the trillions of microscopic organisms that exist on, around, and in us, and which is altogether separate from us genetically. It is generally considered non-pathogenic; in fact, there is a great deal of it we can’t live without. According to hologenome theory, another Spell-Check reject, it plays a big part in our development, physiology, immunity, nutrition, speciation and other bodily systems. It acts symbiotically with the host to provide traits we didn’t need to evolve on our own. Within the body of a healthy adult, these microbes outnumber the host cells by about ten to one, although in aggregate they would only weigh about two or three pounds, the cells being much smaller than human cells.
This is a hot field of research. The findings of the NIH’s recently concluded Human Microbiome Project is providing us with tons of discoveries, some of it quite surprising, and leading to some new ways to look at life on earth. Take medicine, for example. Since the advent of antibiotics, a good deal of medical treatment has been to kill-kill-kill (bacteria, that is). We’ve known for a while that antibiotics have been grossly overused, and that germs have become resistant to them. Now we’re hearing about probiotics (oops! You-know-what again), the opposite of anti-biotics. The general idea is that instead of killing microbes you introduce microbes into the ailing system, which will re-balance the respective microbial population, resulting in a healthy mix–The good guys will hold the bad guys in check. By speciation, mentioned above, I mean that members of some (non-human) species cannot successfully mate with other members unless their respective microbiomes are compatible. Also, our immune systems exhibit a great deal of dependence on our gut flora. It’s been pretty well-established that it is possible to be too clean, that microbe exposure, particularly in children, plays a vital role in the development of a well-functioning immune system, which can provide life-long protection from disease. An important microbial infusion for infants comes from mother’s milk. Some researchers have taken hologenome theory so far as to propose that lactation evolved not as a source of nutrition but for the immunity benefits it confers upon the child.
These are just a few greatly over-simplified examples presented in a slim overview. I could go on forever relating what’s out there on this rich topic. Related articles are popping up just about everywhere you look, in the popular press as well as the more scientific. For what it’s worth, I think big changes are going to come about as a result of this emerging research. We’ll see. For starters, try Googling fecal transplants.