Individualism is supposed to be part of the human experience. Live your life. Think for yourself. Follow your dreams. Well ... it turns out there may be more to "you" than you might expect. Scientists are redefining humans – not to mention plants and animals – as not just the physical form that we can see, but also a biological network of invisible microbes living on our skin and inside our bodies. They say it just might revolutionize the way that doctors treat a wide range of ailments and diseases.
"We wouldn't be who we are without our microbes," says Kevin Theis, an assistant professor in the Wayne State University immunology department in Detroit, Michigan.
A person starts picking up those microbes the day he or she is born, accumulating them in the birth canal and then through skin contact once the baby leaves the womb. Humans continue to develop a stew of bacteria – called the "microbiome" – by acquiring bacteria out in the world through everyday activities like breathing, eating, touching door knobs, shaking hands and simply walking around in public.
Theis and others have been studying the idea of the "holobiont," a term used to describe the concept that a person, plant or animal doesn't just include its own cells and genetic material, but also the microbes that they carry around with them. He says it could change the way we look at evolution, taking into account the way that microbes and the surrounding environment impact development. It could also make modern medicine better equipped to provide individualized treatment.
"You hear a lot about personalized medicine," says Theis, who along with Vanderbilt University biology professor Seth Bordenstein recently explored the concept in a journal article for PLOS Biology. "This would be taking that a step further, because now part of the microbiome is also part of that personalization."
That means looking at both the harmful microbes that could be contributing to obesity and disease, as well as those that boost health and stave off maladies. A whole slew of both type of bacteria are living in our guts, and much of it helps keep us free of things like cancer and obesity.
Symbiosis is the term that experts use to describe the interaction of all of the micro-organisms in the human body, much of which resides in the digestive tract. If that balance gets thrown off, it can lead to disease. That's not to say that genes don't also play a major role in human health. Rather, researchers are turning their attention to how genes interact with the genetic material in bacteria, and how differences in each can impact health.
The idea is that we may be able to enhance our well-being by maintaining the proper bacteria balance. That may mean introducing certain bacteria into the body through diet and probiotics. It may also mean keeping a healthy mix of bacteria in our bodies by refraining from over-cleaning, or the urge that some of us have to constantly reach for the hand sanitizer.