We are not alone

Science News Magazine has been published since 1922, over ninety years. The news arm of the non-profit Society for Science and the Public educates and informs the public about current happenings in science and technology. It has covered such seminal events as the first man-made nuclear reaction, the first electronic computers, man’s first walk on the Moon, and the first jet aircraft. For some time, the editors have selected the top science story of each year.

For 2013, there were plenty of candidates. The amazing rise of miniature unmanned aerial vehicles (drones). Gene therapy advances in managing blood cancers. The ability to grow replacement organs from scratch. The Nobel prize in physics for the discovery of the Higgs boson.

But what was the top science story of 2013? Bugs.

Or more precisely, bacteria and other organisms which make up the microbiota living on and within the human body.

In a steady stream of studies and reports throughout the year, we learned more and more about our remarkable little cousins. For instance, the fact that only 10 percent of your cells are human; the other 90 percent are a mixture of bacteria, fungi, and viruses. (That microbes are so tiny and human cells relatively huge accounts for the fact that, by mass, our microbiota only amounts to a few pounds).

Scientists are even beginning to argue that we should view the human body as a superorganism defined by this mixture of human and microorganism DNA (microbiome). The advantage in doing so is that it might help us better understand the effects of diet, chemical exposure, and other factors on our health.

It is important to note that our community of microorganisms is for the most part beneficial. They help us digest food and convert it more efficiently to energy. They influence the immune system, training it to identify and fight true pathogens. They produce hormones instructing our body to store fats, and create necessary vitamins. To understand the workings of the human body without considering our microbiome is, we are finding, impossible.

Michael Pollan, in an in-depth New York Times Magazine article (“Some of My Best Friends are Germs”, May 15, 2013), details his research into this new frontier. Starting with a submission of swabs to the BioFrontiers Institute at the University of Colorado, he received a detailed report of his personal microbiome. Pollan interviews the scientists involved in the project and describes how our microbiome, unique as a fingerprint, is developed. Soon after birth, a community of microbes takes hold in the infant gut. Its composition from there is influenced by environment and, mostly, diet. In fact, the BioFrontiers scientists can identify from a person’s swab samples both where they live in the world and what is the makeup of their diet.

Researchers have observed that obesity may be encouraged by a certain mix of gut flora. And that mix of flora is a result of diet. Meat eaters have a distinct pattern of gut flora from vegetarians. Diets high in sugars and fats are quickly absorbed, denying nutrition to our little minions. They prefer diets high in fiber and complex carbohydrates; these take much longer to digest. What a surprise, then, to see that independent research into low glycemic index (GI) diets have concluded that diets high in fiber and complex carbohydrates are highly preferable for health. The microbes are the key, and they live or die by our dietary choices.

So what might this flood of human microbiome research mean? Perhaps we’ll find that our war on bacteria, with a plethora of antibiotic soaps and cleaning products, might be taking a toll on our little helpers. Certainly we need to be concerned with pathogens, but perhaps we are overdoing it.

We might find that diet books of the future will focus on cooking for our whole selves. Lightly cooked vegetables, whole grains, al dente pasta, for instance, all take longer to digest and provide the fiber that our gut bacteria thrive on. Feed them well and they will serve us well. It would be a complete change in perspective and provide a grand new toolset for managing obesity and optimizing health.

There is much research yet to do and understanding to be gained. But it is exciting that we are beginning to comprehend the owner’s guide to the whole human being.