Much has been in the news lately about the human microbiome and the implications this research has for our health. For those of you not familiar with the term microbiome, it is the sum of all normal, non-pathogenic bacteria that live on and inside our own bodies on a daily basis. These are very large and diverse populations, so much so that bacterial cells outnumber the cells of our own bodies ten-to-one and it is estimated that humans are host to literally thousands of species of bacteria. This doesn’t even begin to cover the number of viruses that may live in us long term; referred to as a virome. It seems today that we are far more complex organisms than we ever imagined. But what does this complexity mean? Does it have implications in how we should treat disease or why we become sick in the first place?
Our very bodies have adapted to live in harmony with a number of microbial species. The common perception that all germs are bad has quickly unraveled in light of discovering their numerous beneficial functions. Bacteria in our gut help us digest food and make beneficial vitamins for us that keep us healthy. The bacteria on our surfaces prevent pathogens from invading and infecting us. New research is shedding light onto the complex interaction between our microbial communities and our own immune systems. More and more it appears that our past indiscriminate use of antibiotics was not only an ineffective approach, but that damaging our microbial communities with antibiotics could actually harm us as much as the bacteria we aimed to destroy. For years many people have noticed a slew of gastrointestinal side-effects when taking antibiotics and it appears that, in some instances at least, this is directly related to killing off beneficial species in our intestines that have anti-inflammatory properties. Some women may also be familiar with side-effects of antibiotics such as yeast infections. Once again, it appears that these result because antibiotics can kill off beneficial species in this area, leaving an open niche for pathogens ( i.e. yeast) to repopulate the region. Further involvement of our microbiota is being studied in relation to allergies, immune development, and even resistance to some diseases.
This is a very exciting time for research in this area as scientists now have the necessary tools to answer these questions. With the advent of high throughput sequencing and methods of detecting bacteria that do not require culturing in the lab scientists have been freed to do the very first comprehensive surveys of our own microbiota. These preliminary results are both surprising and profound. Initial steps are also being taken to characterize all of the viruses that we are host to in our virome. This also promises to shed further light on how our bodies respond and adapt to the presence of foreign invaders. Expect to see much more research in this area and deepening understanding of our own function in relationship to our personal ecosystems. This is truly an exciting time to be a microbiologist.