Many reports have recently popped up claiming that some bacterium is going to cause the next great human health crisis, cure cancer, or even help you lose weight. Here are 5 fun facts about our microbial companions that will put things into perspective.
1. Bacteria are astoundingly small
Bacteria are microscopic (0.5-5 microns in size). So small that nearly one thousand would be able to fit inside the period at the end of this sentence. It is therefore not surprising that they weren’t discovered until the mid-17th century. Since then, it has become indisputably clear that our species’ past, present and future are delicately intertwined with these creatures.
2. There is almost no place on Earth without bacteria
It is estimated that 1030 bacteria cover our planet. That is a hard number to imagine, but if a single E. coli bacterium weighs 665 femtograms (10-15 grams), then the total mass of all the bacteria on the planet is .67 exagrams (1018 grams).
Still having some trouble wrapping your head around this number? This quantity exceeds the total mass of every plant (grass, shrub, and tree) on earth!
This astoundingly large population is comprised of over a billion different species (only a small minority of these has been characterized). They reside in the soil, across the ocean’s surface, floating in the atmosphere, in our hospitals, on our desks, and even within our own bodies.
3. The majority of bacteria are not harmful
Don’t let the previous fact incapacitate you. Despite their prevalence, the majority of bacteria present no threat to humans. In fact, bacteria play a number of instrumental roles both in nature and in human health. They are responsible for nourishing and processing the soils in which all plants grow, they provide a large majority of oxygen to our atmosphere, and the symbiotic bacteria that live inside us assist our bodies in breaking-down food, warding off obesity, thwarting pathogens, and synthesizing vitamins.
4. But, some bacteria are really bad
Although they represent the minority, pathogenic bacteria are the best understood, and responsible for some of the most devastating diseases plaguing our planet today. Many third world countries still suffer from outbreaks of Cholera, Shigella, Pneumonia, and Tuberculosis – often brought about by high human population densities and poor sanitation.
Presently, our strongest weapon against bacterial infections are antibiotics. These are molecules that interfere with a bacteria’s ability to grow and replicate. While the discovery of antibiotics was one of the most important medical advances in history, scientists are quickly discovering the negative implications of their use. Not only do antibiotics purge our bodies of ‘good’ bacteria, but the more we use these wondrous drugs the faster bacteria figure out how to elude their toxic effects. This evolutionary tug-o-war has given rise to bacterial strains with resistance to almost all known antibiotics. In some cases this resistance is so devastating that these mutants can shut down entire hospital wards.
5. Bacteria are the ancestor of all living things on earth
It is now generally accepted that the first living things on our planet were “bacteria-like”. That is to say that they were robust, single-celled, self-replicating systems with a knack for adaptation and evolution. One of the evolutionary paths these early microbes took led to humans. But we share more than just history with bacteria – human beings contain more bacterial cells than human cells.
This means that we not only co-evolved with these microbes, we formed an interdependent pact with them. As we continue to learn more about the ‘good’ and the ‘bad’ aspects of bacteria, it is imperative that we keep in mind the delicate relationships that we have forged with our tiny companions.
I hope you now see the truly surprising headline would be one that claimed bacteria didn’t influence some facet of our existence!
Image Credit: False color tunneling electron microscope image of different types of bacteria present on a human tongue.