The forgotten organ and the mighty midgets

The term bacteria or microbes has become very common but often induces in layman's mind a sort fear as if they are the only cause of diseases and that we should keep away from them. First, I would clarify this before proceeding further. It's true that some microbes ( viruses, bacteria and microfungi) do cause some diseases referred as Infectious diseases some of which can be contagious as they spread by contact. We have a number of antimicrobial drugs to treat such diseases. But there are other types of diseases termed physiological and genetic diseases which are not caused by microbes and are often more difficult to treat such as Cancer.
We need to be ever grateful to these mighty midgets or microbes, as we cannot survive in this world without them, while they can without us. Apart from varied uses of microbes in the production of several goods and services, the very space where we live is available to us only because of them, as they keep constantly removing the dead biota (organic matter) from our environment. If only we sterilize our environment, the space available would soon be filled with dead ones.
At this juncture, I would like to point out to some of you that not only we can't afford to keep our environment complete sterile but can not afford to keep any part of our body either outside or inside totally sterile. Every part of our body from head to foot both outside and inside is inhabited by specific populations of microbes which are irreplaceable as they perform specific roles needed for our survival. These are called "Microbiomes" and dependant on the place of occurrence they are variously labelled as Gut Microbiome, Skin Microbiome and so on. In fact, on a healthy, normal human body the number of natural resident microbes far out number the number of cells in the body. The microbial inhabitants of the human organs such as the gut is often referred as the forgotten organ because they perform and are responsible for a variety of essential functions. The microbial signature is often specific helping us to characterize an individual for example the gut Microbiome will tell us about your food habit. At this juncture, it would not be out of place to say that the cattle which eat and digest hay ( dry straw) are able to do so only because of their gut microbiota and not because of their ability to produce the enzymes required for straw digestion.
When I start talking or writing on this topic, I am likely to forget myself and over step the limit of general knowledge and get into technical details. So I force conclude this topic and express my willingness to answer specific queries if any from any of you.