Wonderful world of microorganisms and their role in human life.


The wonder of our life is somewhere embedded in small things. The best example is our own body cell. Cells are the "building blocks of life. If in a human body there are 100 trillion cells, then it is nothing but a wonder! 100 trillion cells together build human body, but if we look at microorganisms like bacteria, protozoa, virus etc, they are life but wih a single cell itself and that is another wonder of small things.

Microorganisms play a very crucial role in our body. These single cell bacteria produce many vitamins that are vital to our body and without which many of our metabolic activities are affected. One of such Vitamin K2 also known as menaquinone, menatetrenone is produced by bacteria called E.Coli that live in human gut. The human body carries about ten times more microorganisms in his body as to that of the 100 trillion cells that he has of his own. The role these bacteria play in our intestine resembles to any organ that is why scientists call this as "forgotten" organ. One of the estimation is that these gut flora have around 100 times as many genes in total as there are in the genome of human being . There are about 300 to 500 different species that live in the gut of various animals.

In 2009, INRA (France) scientists evaluated the existence of small number of species that are shared by all individuals constituting the microbiota phylogenetic core of human intestine. These include the genera Clostridium , Fusobacterius, Bacteroides, Peptostreotococcus, Peptococcus and Eubacterium. Other genera like Escherichia and Lactobacillus are present in less extent.

The major source of nutrients and energy is provided by bacteria when they ferment carbohydrates into short chain fatty acids also know as SCFAs. When SCFAs are produced by fermentation, it is called as saccharolytic fermentation. Lactic acid and gases are produced by saccharolytic fermentation and include many organic acids like butyric acids, acetic acid, propionic acid etc. which are necessary for human growth and normal functioning of various organs. Muscles uses acetic acid , Liver can produce APT energy only with the help of Propionic acid and prevention of deadly diseases like cancer is done as butyric acid which provides energy to gut cells .

Another miraculous activity by gut bacteria termed "barrier effect "is preventing colonization of species that can harm human host . Species like Clostridium difficile and some yeasts which are harmful and cause disease known as pseudomembranous colitis.But these harmful bacteria are unable to overgrow because of competition from helpful flora of gut. Thus animal without gut flora is easily infected with these pathogens.

The list of role of microorganism in human life is long and their contribution is wonderful. Today's many antibiotics which cure the deadly diseases are result of many bacteria as they produce them. One well known example is Penicillin and related derivatives. In our daily routine, bacteria called Lactobacillus convert milk into curd.
Many fermented food products are results of enzymatic activities by bacteria. One should also know that not all the microorganisms are useful. As all the fingers of our hand is not similar, the same way all the microorganisms are not useful. There are many microorganisms including many bacteria and viruses which can result in deadly diseases their infection occurs in human and also animals. The phrase "Small is powerful" is true and microorganisms are live examples of it & really, the wonders of life are always hidden in small things!

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