The Human Microbiome

Human Microbiome Definition

In my research, I keep seeing the word “microbiome”.  Not knowing what this was, I began looking to find a human microbiome definition that could be understood by someone not in the medical profession.  The human microbiome is truly a phenomenon and proves to me even more just how truly magnificent our body is!

Definition of the Human Microbiome

Did you realize that only 10% of the cells in our body are “human”?  Actually, we share our life with about 100 trillion organisms which comprise something called our microbiome.  For each cell in our body, there are 10 microbial cells living either inside or outside it.  These are all essential to our existence.  This complete dependence on the microbiome within us has led many experts to believe we are truly more of a “super organism” than simply “human.”  We humans are mostly microbes which outnumber our human cells ten to one.   And the not-surprising fact is the majority of them live in our gut!

What Exactly Is a Microbiome?

The word “microbiome” is defined as the collection of microbes or microorganisms that inhabit an environment.  Our human microbiome is made up of communities of symbiotic, commensal and pathogenic bacteria (along with fungi and viruses).  These communities exist in unique, complementary blends and inhabit all parts of the body from the skin to our mouths and eyes and our intestines.  The clusters of bacteria from different parts of the body are known as microbiota.  For example, you’ve heard of skin microbiota and oral microbiota and gut microbiota (also known as gut flora).

Functions of Three Bacteria Communities

The “symbiotic bacteria” mentioned in the preceding paragraph offer a mutually beneficial relationship along with the “commensal bacteria” which is along for a free ride.  Then there are the “pathogenic bacteria” which are fewer in number and considered to be disease-causing opportunistic microbes.  However, these pathogens do not always cause disease and some of them have beneficial effects within the body.  What scientists have determined is that the makeup and overall health of the body’s microbiome as a whole determines whether the pathogens in the gut co-exist peacefully or cause disease.  Please note that the gut is mentioned specifically here.  All three of these bacterial communities make up an essential piece of our biological puzzle.

What Is The Benefit?

The communities in our microbiome carry out a variety of functions which are vital to not only our health and well-being but to our very survival.

Starting with our immune system, our microbiome establishes the parameters in which our bodies judge whether or not something is friend or foe. It maintains harmony, balance, and order within its own communities, ensuring that opportunistic pathogens are kept to a minimum, while also keeping the host system from attacking itself.

The microbiome is our first, second and third line of defense – starting with our skin, then our mucus membranes, and finally our gut, providing a living barrier that is able to be modified and transformed to suit individual needs and unique environments.

Our gut microbiota is fundamental to the breakdown and absorption of nutrients. Without it, the majority of our food intake would not only be indigestible, but we would not be capable of extracting the critical nutritional compounds needed to function. Our symbiotic bacteria not only provide this service, but also secrete beneficial chemicals as a natural part of their metabolic cycle.

Where Does Our Microbiome Come From?

You’ve heard the statement, “We are a product of our environment.”  How true that statement is.  As infants we (and our guts) come into this world with a blank slate of sorts, awaiting our first contact with the microscopic organisms which surround us.  Our first exposure via the birth canal, followed by a gut-nurturing concoction of mother’s milk, is nature’s way of establishing the foundation on which we will build our microbiome. Familial, dietary, and environmental exposure throughout our developing years cultivates an ecosystem which will play a starring role in the determination of our health for a lifetime.

In fact, every time you kiss someone, every time you pet an animal, each time you eat a meal or apply a cosmetic, you are affecting the composition of your microbiome.

Why Is The Microbiome Important?

Antibiotics and an obsession to sterilize our environments (think of all the chemical-based products used) have resulted in a significant rise in gut-related illnesses as well as pressure on the medical community to finally explore this long-ignored aspect of human biology.

Research has uncovered an intricate web connecting our gut flora to virtually every process in our body.  As such, imbalances in our microbial communities have been implicated in countless health issues, including immune health, psychological well-being, and some of the deepest chronic health issues of our times.  There has been research in the gut-brain connection which may well revolutionize the way psychologists view mental and emotional well being.

Techniques and methods on how to manipulate one’s microbiome have begun to flood medical literature. Trading gut bacteria has become the latest focus for therapeutic treatments, being successfully utilized as a means to treat antibiotic resistant infections such as C. difficile, and going so far as to be considered as a potential means of treating obesity.  One researcher, Martin Blaser, Professor of Microbiology at the New York University School of Medicine and founder of the Foundation for Bacteriology, is advocating good bacteria as “the new antibiotics.”  Since the microbiome was not generally recognized to exist until the late 1990’s, you can see this is still a relatively new area to explore.

In Summary…………

  • The bacteria in the microbiome help digest our food, regulate our immune system, protect against other bacteria that cause disease, and produce vitamins including B vitamins, B12, thiamine and riboflavin, and Vitamin K, which is needed for blood coagulation.
  • The microbiome is essential for human development, immunity and nutrition.
  • The bacteria living in and on us are not invaders but beneficial colonizers.
  • Autoimmune diseases such as diabetes, rheumatoid arthritis, muscular dystrophy, multiple sclerosis, and fibromyalgia are associated with dysfunction in the microbiome. Disease-causing microbes accumulate over time, changing gene activity and metabolic processes and resulting in an abnormal immune response against substances and tissues normally present in the body.
  • Autoimmune diseases appear to be passed in families not by DNA inheritance but by inheriting the family’s microbiome.
  • The importance of protecting and maintaining a properly functioning microbiome cannot be stressed enough.  A healthy diet accompanied by appropriate supplements are so very important to keep our human microbiome in a condition that will benefit our children and their children.

I do hope this article has given you understanding of what the human microbiome is and the extremely important part it plays in our existence.  Please do offer any comments you have on this topic.




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