Microbiome can be defined as the sum of microbes, their genetic genomes and their environmental interactions in a particular environment. The word Microbiome was inverted by Joshua Lederberg, one of the giants of molecular biology to designate all microbes. He emphasized that microorganisms inhabiting the human body should be included as part of the human genome, reason on the influence on human body physiology (Predator, 2012).
However, microbes are seen to be the dominant life form of Earth. Its bacteria organisms which live on the plant are outnumbering all other bacteria combined. According to Joshua Lederberg, Microbiome bacteria dominate not only the planet, but also new people. However, the body of each one of us is ten (10) times more microbial cells than other cells which are contained in the human body (Predators, 2012). Therefore, the number of microbial genes in the human body is one hundred and fifty (150) times than that of human being genes (Predators 2012).
In addition, it's clear all these are living in the human being body and its out cover forms an ecosystem which is "Microbiome" and therefore symbiosis of these small human being with cells normally do create a true "super-organism." Besides, Microbiome do exist in many other environments such as soil, seawater and freshwater system. This therefore, makes it the most densely existing bacteria on earth.
Its however, these bacteria that form our digestive tract known as "Microbiome" normally colonized as early as twenty four (24) hours after we are born, stabilized probably when we are two years old, and therefore they become permanent in our lives and form a true body. Again, scientists have discovered that babies are covered with microbes which are naturally present in the birth canal, while those who are born by Cesarean section are covered with germs that are normally on the skin of the adult (Predators, 2012).
Microbiome link to mammalian
Our bodies are compost with the largest component of Microbiome bacteria than any other bacteria on earth. However, that includes the mouth, hair, nose, ears, lungs and skin which have their own unique Microbiome. This is because Microbiome is mostly transferred from one human being to other especially at birth from mother to child (Kellyn S. Betts, 2011).
More recent, scientist documented those differences in the Microbiome of infants who are born vaginally and by caesarean section, as dominant. They said that the Microbiome pass through several processes during the initial years of life after birth and after that remain relatively constant throughout the entire life of the person until he or she get to the age of sixty five (65) (Kellyn S. Betts, 2011).
Moreover, in adulthood the composition of microbiomes is influenced with various factors not only by host genetics but also by the environment, diet and genes. If the composition of a microbiome changes, the range of services it provides its human host also may shift. However, Lita Proctor, a coordinator for the National Institutes of Health's Human Microbiome Project,8 says the key bacterial organ is the intestinal microbiome; variability in this microbiome may be an important source of individual variability in human health and disease (Kellyn S. Betts, 2011).
In addition, our relationship with bacteria such as microbiomes that live in us is symbiotic, human contact them in exchange for food, and they assist in food digestion, production of vitamins that our body need to strengthen the immune system. To coexist with our microbiome, the immune system must tolerate thousands of species of bacteria harmless. Instead, these bacteria play an important role in the fight against pathogens, bacteria that we contact in our daily activities (Jeffrey Gordon, 2010).
Microbes are so successful on the planet because they don't limit their gene exchange to reproduction. The do share genes across all kinds of habitants and under all kind of conditions. They make this successful by sharing snippets of DNA known as plasmids, a process which is known as horizontal gene transfer, this therefore has nothing to do with reproduction. However, Microbes normally operates it very well and microbes do it a lot (Proctor, 2012).
However, plasmid sharing is one way that bacteria develop to resist antibiotics and to agents that threatens their survival, including metals. In a situation where small intestinal bacteria are continuously exposed to a metal such as mercury, those bacteria with genetic machinery that enable them to tolerate the metal are more likely to survive and reproduce (Proctor, 2012).
In analyzing Microbiome cells as human cells in our bodies. There are 10X many microbial cells in the body. However, we constantly learn several about how changes in the composition of these communities of organizations such as Microbiome which are correlate with human health. Furthermore, studies have shown that disruptions in our Microbiome may influence the course of particular disease states.
Large variation in bacterial lineages between people
It's analyzed by scientist that the rate of decrease cost and increase speed of DNA sequencing, coupled with advances in the computational approaches used to analyze complex data sets which are used for DNA analysis. This has prompted several research groups to embark on small-subunit that is ribosomal RNA gene-sequence-based surveys of bacterial communities that reside on or in the human body, which includes on the skin and in the mouth, oesophagus, stomach, colon and vagina (Peter Turbugh, 2010).
The concept of a core human microbiome
The core human microbiome (red) is the set of genes present in a given habitat in all or the vast majority of humans. Habitat can be defined over a range of scales, from the entire body to a specific surface area, such as the gut or a region within the gut. The variable human microbiome (blue) is the set of genes present in a given habitat in a smaller subset of humans.
This variation could result from a combination of factors such as host genotype, host physiological status (including the properties of the innate and adaptive immune systems), host pathobiology (disease status), host lifestyle (including diet), host environment (at home and/or work) and the presence of transient populations of microorganisms that cannot persistently colonize a habitat. The gradation in colour of the core indicates the possibility that, during human micro-evolution, new genes might be included in the core microbiome, whereas other genes might be excluded (Joseph, 2010).
Humans as Microbial Depots
However, virtually all multicellular organisms live in close association with surrounding microbes, and humans are no exception. The human body is inhabited by a vast number of bacteria, archaea, viruses, and unicellular eukaryotes. The collection of microorganisms that live in peaceful coexistence with their hosts has been referred to as the microbiota, microflora, or normal flora. The composition and roles of the bacteria that are part of this community have been intensely studied in the past few years. However, the roles of viruses, archaea, and unicellular eukaryotes that inhabit the mammalian body are less well-known. It is estimated that the human microbiota contains as many as 1014 bacterial cells, a number that is 10 times greater than the number of human cells present in our bodies (Joseph Gordon, 2010).
The microbiota colonizes virtually every surface of the human body that is exposed to the external environment. Microbes flourish on our skin and in the genitourinary, gastrointestinal, and respiratory tracts. By far the most heavily colonized organ is the gastrointestinal tract (GIT); the colon alone is estimated to contain over 70% of all the microbes in the human body. The human gut has an estimated surface area of a tennis court (200 m2) and, as such a large organ, represents a major surface for microbial colonization. Additionally, the GIT is rich in molecules that can be used as nutrients by microbes, making it a preferred site for colonization (Predators, 2012).