Do Bacteria play a positive role in our Health?
There are bacterial populations that inhabit nearly every exterior surface of the human body (including the outer layers of the gastrointestinal tract). These bacteria play a number of important roles in human physiology. One important role that the bacteria play in the human digestive tract is assisting with digestion. Often, the gut flora is able to break down carbohydrates and some other nutrients that humans may not be able to easily digest. After digestion by the gut flora, these nutrients can be absorbed by the body for use. In the gut, the immune system continually tests these bacteria and allows them to remain there so long as they continue to function in a healthy manner. A secondary benefit of our normal bacterial flora is that they help to prevent pathogenic bacteria from colonizing. In a competition for resources, an already established colony will easily out compete newcomers and prevent them from gaining a significant foothold.
Externally, bacteria play important roles as well. Without the work that bacteria does in the environment, we would very likely not be able to survive. Bacteria play roles in degrading plant and animal material and in soil formation. This has important implications for agriculture and economic development. In addition, we use bacteria in order to produce many drugs (including insulin) which are used to treat illnesses in modern health settings. Through the study of bacteria, new and important discoveries are made every day that help to illustrate the positive role that they play in human health.
Typically, disease will only arise if pathogenic bacteria enter the body or the normal microflora that the body hosts migrate to a location they do not belong. Some of these pathogenic bacteria may actually be normal flora of the human body that have become pathogenic due to a compromised immune system. These pathogenic bacteria are known collectively as opportunistic pathogens (because they must wait for an opportunity to become pathogenic). It is important to note that no bacteria are inherently 'out to get' humans, we just provide an environment that some of them are able to thrive in. These bacteria are simply trying to survive and reproduce, not to purposefully cause harm.
It is important to note that no two people will have the same makeup of internal flora. The exact makeup of an individual persons bacterial population will depend on the environments that the given person inhabits, the types of food that person ingests, and a number of other factors. Usually there are differing rations of the same bacteria among different people, however, and the same bacteria are generally found to be pathogenic regardless of the internal flora that person has. Bacteria play an important role in our everyday lives and they enable us to live in a way that we may not have been able to without them. One interesting fact that may be noted is that even the mitochondria, the 'power-plant' of our cells, is thought to have once been a bacteria that was taken into another and began something like a symbiotic relationship and, thus, allowing larger and more complex cells and organisms to form. Overall, bacteria play a more positive role in our health and environment than a cursory glance would seem to indicate.
Written by : Alexander Maness, United States (M.S. in Biotechnology )
Edited by: Rajesh Bihani ( Find me on Google+ )