…decoding human microbiome might be at least as important as the decoding of the human genome.

It is a well-known fact that bacteria in our organism way outnumber human cells. The ratio is ten to one in favor of these tiny microorganisms. Their colonies cover our body inside-out.

Their sheer number makes us think we might be more bacteria than human. So, could it be they are the ones running the show of life around here? After all, they are the earliest forms of life on our planet, playing a great role in shaping the environment for all living organisms ever since. Could it be that the answer to our medical problems and the human longevity lies in the aggregate of microorganisms living in our bodies, and not in human cells? So far, this idea was poorly researched.

Apart from aiding digestion, human microbiome, that includes bacteria, fungi and archaea, might also be a contributing factor to our body’s defense system against infections, reproduction processes and the brain development. New findings in many ways changed our previous understanding of these tiny beings which, until recently, were unfairly attributed the only role of bodily odor producers. In fact, it might be that these creatures are as important for the human evolution and the individual state of being as our own cells. Human is a product of a symbiosis of human cells and microorganisms.

Recent findings of Martin Blaser, professor of medicine and microbiology at NYU’s Langone Medical Center, published in the mBio, journal of the American Society for Microbiology, under the title “Host demise as a beneficial factor of indigenous microbiota in human hosts”, suggests that microscopic communities cohabitating in our bodies with much larger human cells might have greater role than previously ascribed by scientists.

Blaser’s lifetime research on Helicobacter pylori, a bacterium living in the guts of more than a half of human population, helping regulate levels of stomach acid, lead him to establish a hypothesis that “a real symbiont is an organism that keeps you alive when you are young and kills you when you are old.”

Based on Blaser’s hypothesis, Glenn Webb, professor of mathematics at Vanderbilt University, developed mathematical models which showed that the decrease in number of the elderly people contributes both to the human species and bacteria, by allowing juvenile population greater share of food and other resources, which in turns produces stronger humans as a more stable and suitable host for bacteria.

Another article, published in Science Daily on March 22, reports about the recent success of a team of researchers at Vanderbilt University who programmed bacteria to generate molecules that could suppress hunger and become a potential long-term solution for fighting obesity. According to the article, a number of studies have shown that microbes living in our guts are the key determining factor for obesity and related disease and that altering the gut microbiome may greatly help improving human health.

It might be a far-fetched laymen hypothesis, but, if we combine findings from the two previously mentioned studies, which say that the human microbiome influences not only the function of our gut, but also our cognitive functions, reproduction, and ultimately, human lifespan, and the possibility to alter the bacterial genes, than microbial engineering could be the solution for various therapeutic treatments in humans that so far have been mainly focused on human genome research.

Finding a universal solution to fit all humans probably won’t be possible, but decoding human microbiome might be at least as important as the decoding of the human genome.

That this task won’t be an easy one shows a study conducted by Patrick D. Schloss, associate professor of microbiology and immunology at the University of Michigan and Tao Ding, post-doctoral research fellow at this University, published in Nature earlier this month. It reveals that, each person hosts a specific and varied collection of bacteria which is a result of a multitude of personal and environmental factors. Understanding the mechanisms behind this individual particularity would allow for better personalized medical care in the future, and a coordinated effort with the research of human genome to extend human lifespan.