What are you? A human being, of course, but what is a human being? Let’s leave out the debate over the invisible, intangible aspect of you for the moment, that is, the “being” and look simply at the “human” part of the equation, your physical body. What are you, physically speaking?

Biology textbooks tell us that we have a human body. That body is the entire structure of a human organism, and it consists of roughly 100 trillion cells (in an adult body) organized biologically into tissues and organ systems. Most people probably operate under the belief that their bodies are complete in and of themselves, that their organ systems are capable of regulating their internal workings, assuring adequate digestion, energy production, detoxification, oxygenation and so on.

Moreover, most people, particularly in the Western world, would think of microbes in the body as being pathogens, or dangerous foreign invaders. The demand for industrial and institutional cleaning products in the U.S. is forecast to hit $10,000,000,000 in 2012, largely due to fears about widespread concern over disease transmission and frequently tainted food supplies.

Put simply, we as a society have become so terrified of bad microbes that we’re no longer making rational choices at the checkout counter. For example, consumer demand for hand cleansers formulated with antibacterial agents such as ethanol, isopropanol or triclosan has grown tremendously over the last few years, despite scientific findings that antibacterial products do not offer greater protection from microbial threats than conventional products, that is, plain old soap.

Widely held beliefs, however, do not always prove to be true. Recent research into the human biome has yielded a number of discoveries that threaten to change the way we look at ourselves and the world around us. While working under the belief that we – and our masterfully arranged 100 trillion cells – had everything we needed to maintain health, scientists often overlooked the wide variety of the more benign microbes and tended to only study the more apparently harmful ones.

A new class of powerful medicine, antibiotics, drove this mindset deep into the science of medicine and many other fields of related scientific inquiry. As Foster and Raoult noted in their 1974 study “Early descriptions of antibiosis“:

The ‘discovery’ of penicillin by Fleming in 1928 and its dramatic production, urged on by the necessities of war, heralded a new era of therapeutics. It has changed the pattern of disease, the prognosis of infections, the expectation of life, indeed, it has changed the whole human ecology.

Exactly how antibiotic use is changing the human ecology and the way the body works to regulate itself, some 100 years after it was given a warm embrace by the medical community, is just starting to be understood. It turns out that the supposedly benign microbes, which incidentally compose an overwhelming majority of the body’s microbiome, are much more important to the body’s regulatory mechanisms and basic physiological processes than previously imagined.

Research over the last 5 years in particular is pointing to the fact underestimating the value and importance of our body’s ecosystem and upsetting the balancing act performed by our microbiome and our immune system (if the two can really be seen as separate) may just be one of those roads to hell paved with good intentions.

It is widely known that our bodies are roughly 70% water. A lesser known fact, because it was only recently discovered, is that bacterial cells outnumber the body’s cells 10 to 1. You are mostly water, but you are also mostly made of foreign microbes. These bacteria and other microorganisms do not hurt us, in fact, they are essential to just about every one of our body’s functions. Antibiotics, a term which means “against life,” are undoubtedly life savers when used properly, but scientists have yet to confirm if we are using them properly at this point.

The question hanging in the air is whether or not we are upsetting balances in this broader concept of what the human body is that will be difficult to restore, or to put it in more specific terms, if the approach we’re taking is not one of the root causes of many of our modern epidemics (e.g. obesity, cancer, autoimmunity, mental illness, etc.)?

Time will tell.