Who are we?

Louis Brossard.

26 June 2012

There is a whole new concept of who we are. The concept of nature or nurture is superseded now. We are all much more than we thought we were. Consider that there are ten times more external cells that came to us from outside of our bodies but are essential to our being than our own generated cells. These are the bacteria, viruses, fungi, and other microbes that are on and in our bodies. Some of them are necessary for us to stay alive. This is our personal microbiome. Yet their DNA didn’t come from either our father or mother.

Philosophically we now must redefine who we are. To omit 90 percent of the cells of our being (by count, not weight) that make up an essential part of that being is nonsensical. These cells have a profound effect on who and what we are. Without them we cannot survive. Yet they have been ignored or feared for most of our existence. Only recently are we realizing the essential influence they are to our life processes. We now realize that our genome is not complete without the genome of the microbiome that is part of us.

So who are we? Would a murderer have been a great philanthropist if he had been exposed to a different group of bacteria? That’s a profoundly discomforting contemplation. If we take a systemic antibacterial treatment in a completely different environment like a primitive culture are we likely to become a different person? There is ample anecdotal evidence of such changes because of a near death illness. It will be difficult to do controlled experiments to test such an idea. How much of evolution has been directed by our microbiome?

 Historically medicine has looked for specific microbes which are known causes for disease. The Mycobacterium tuberculosis gives you tuberculosis; but not everyone. Is that because of our bodies antibody defense or is it because some other bacterium in our body is impeding the deleterious one? It’s a whole new concept of what our body is.

The medical, social, philosophical and self-image aspects of this concept are fascinating. Dogs have always known this. We now have dogs that support diabetics by smelling when their blood sugar is low and dogs who can warn an epileptic of an impending attack. It is very likely that a dog can track a person by their microbiome smell rather than their intrinsic cell smell. They instinctively know that they are the same.

When we shake hands with another person we are sharing some of our microbiome. We share even more when we kiss another passionately. A family shares a good part of their microbiome. And there is even an experimental treatment for some bowel disorders by literally transferring some of a well person’s microbiome by injecting fecal material from them into the affected person’s intestines.

We must have these microbes to live. What we must learn is which groups are good for us and which are bad for us. With all the infinite possibilities of such a large group of players it will be extremely daunting to make sense of it all. A whole new scientific-medical discipline is beginning. What a fun time to be a microbiologist.