Our Invisible Partners

I remember as a kid, there was a family living next door with a flawless skin, pure sets of white teeth and crystal clear white eyeballs. I thought if I could wash my teeth with a bleach, my skin with detergent instead of the gentle shower gel and as well wash my eyes with toothpaste, I would attain the perfect skin of my neighbors- Thank God I never did.

Our human body is very fragile and tender- you can't just apply whatever you wish to it. This is owing not only to the chemistry of our human flesh but also to its biology. Our human body can be described as a whole ecosystem of its own composed of different cells, foreign and native. In biology classes, we are made aware that the functional unit of a living organism is the cell. We are indoctrinated with the scientific fact that the body of a multicellular organism is made up of numerous cell and sometimes can be differentiated. Differentiated cells are not similar in function, instead they are diverse in shape and size all working towards the functional existence of the organism as a whole.

_{Licence: Public Domain --- Source: Wikimedia}
A multicellular organism like an human being is composed not only of human differentiated cells but also a significant population of foreign cells, the micro-organisms. Recent studies has proved that the number of micro-organism cells in an individual supersedes that of human cells in ratio three to one. Their cell size howbeit is smaller compared to a typical human cell making their number less significant in mass.

Micro-organisms are a principal part of our lives as human. They are not just part of our lives but take up crucial role in the lives of every living organism. You might have heard of the medical fact circulating the internet that women shouldn't wash their vagina with soap, save only water. This is not an hoax. Using whatever type of soap irrespective of its skin-tenderness, changes the normal pH and biota of the vagina. A pH of 4.5 is required to prevent growth of harmful organism, and the bacteria lactobacilli making up the biota is required in maintaining this pH. A disturbance of the pH and vaginal bacteria can lead to an inflammation or infection.

So what are micro-organism? Micro-organism are believed by many to be living organisms that can not be seen with the naked eye except with the aid of a microscope. This is partially true but not all microscopically visible organisms are micro-organism. Viruses for example are complicated assemblies of molecules which act like living organisms and non-living organisms. Outside a living cell, they assume a crystal form and can not exhibit live processes. Viruses upon introduction to living cells assume living function. Though microscopic, the are not classified as micro-organisms- this fact is however controversial as some scientist claim they are still micro organisms.

Another interesting group of microscopic organisms are the micro-animals. Like the name insinuates, they are animals but invisible to the naked eye. Dust mites for example, are micro-animals that live in dusts particles. A typical dust mite measures between 0.2 and 0.3 millimeters in length. House dust mites feed on human skin flakes and are also responsible for many allergic reactions to dusts. Spider mites are another example of micro-animals with sizes less than 1 millimeter. These animals also make webs and feed on plants.

Micro organisms are also called microbes. They are microscopic organism which may exist as simple cells or a colony of cells. The The study of micro-organism is called microbiology. It began to take its form when some people began to suspect a world of tiny invisible creatures living in our world and affecting our lives in some ways. These supposition can be found in ancient books like the Jain scriptures from the 4th century BC and the book on agriculture by Marcus Terentius Varro. In his book of homesteading, the ancient Roman scholar warned against locating a farm near a swamp as there are small invisible creatures which float in the air and gain access into the body through the mouth and nose, causing harmful diseases.

With the invention of microscopes by Antonie Van Leewenhoek, there was an avenue to prove the existence of these creatures. Microbiology which is a study of micro-organisms began in the 1670s by Antonie Van Leewenhoek. After that, many other discoveries which was to bring microbiology to its present state began unveil. Louis Pasteur in the year 1850 discovered that micro-organism are responsible for food spoilage. Before this, there had been a theory known as spontaneous generation in the science world. It claimed that living organism arise from non-living organisms like dusts and sands. With Pasteur discovery, the spontaneous theory was debunked and this also shaped the evolution of cell theories.

In the year 1880,Robert Koch was to discover that microbes were responsible for the tuberculosis, cholera and anthrax epidemic. Tuberculosis was assumed to be an inherited diseases, convinced that it was caused by a bacterium went on with an experiment with guinea pigs. This experiments proved his hypothesis right and he went further to publish his findings. Robert Koch was the father of modern bacteriology which is a branch of microbiology. He also stipulated the concept of infectious diseases as well as supporting with experimental evidences.

Micro-organism are found everywhere, in the driest land, humid places, water, air and our body as humans. Some are adapted to extreme conditions such as very hot or cold and even high pressure places. Deinococcus radioduras is adapted to radiation environments.

They are important in human culture. They help in producing fuel such as algae oil, enzymes and bioactive compounds. They are also employed in biological war- this is the use of biological infectious agents including toxins with an intention to kill or incapacitate plants, animals or humans as an act of war. Fermentation of milk is also a vital function of microbes in human culture.

_{Distribution of the natural flora/ micro-biota of the human body. These organisms are not harmful to the human homeostasis. Animals such as rats have their natural flora too which also projects no threat to their system. But upon introduction to the human body posses great threat of a disease outbreak.
Licence: Public Domain --- Source: Wikimedia}
Not all micro-organism are pathogenic or destructive. We depend on bacteria for our food digestion, medicines, plant growth and so on. Micro-organisms that form endosymbiotic relationship with the human cells are far from being harmful though not compulsorily beneficial. Some micro organism play crucial role in the defense system of human against other pathogenic micro-organisms, this is known as microbial symbiosis. The micro-organism found in the digestive tract not only participate in microbial symbiosis but also help in digestion processes. These microorganism help in fermenting food, synthesizing vitamins and as well maintain homeostasis.

The human microbiota describes the taxonomic composition of micro living organism living in the human body. They are present typically everywhere in the body. The microorganism in the eye, nose and mouth are similar. These microorganism population supersedes the population of humans on the globe, yet the eye is considered clean and need no further soapy cleaning. Disrupting these natural microbiota or flora can lead to adverse consequences.

We cant deny the symbiotic relationship that has existed between microbes and human from the beginning of days. Laboratory experiments are conducted on microbes to improve our health. Microorganisms are sometimes intentionally introduced into an organism for it health benefit. I guess the WHO needs a new date in their calendar- "The World Microbes Day!".

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Further Reading

• _{Micro-organism}
• _{Microbial Symbiosis}
• _{Human Microbiota}
• _{Eyes need no additional washing}

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