Episode #3: Less Than Half Our Body Is Human Cells

Bacterial cells on the intestine.
Ever thought about how many cells make up your body?


I have read that less than half of our bodies are made up of human cells.  The rest are all sorts of weird and wonderful creatures that you may not want to know about.  Do you think this is true or false?


Bugs that live on us and in us

The claim doesn’t seem unreasonable when you consider that around 39 trillion microbial cells live in us or on us.
Due to their small size, these organisms make up only about 1-3 percent of our body mass. This translates into about 1-3 kilograms. It also belies the enormous capabilities of what is called our microbiome.


For simplicity, we will call all these creatures (bacteria, viruses, and fungi) ‘bugs.’


Apart from the bugs, around 1.5 million face mites (that belong to a group called ectoparasites) normally live on our bodies.  They are tiny spiders you pick up as you age. By age 60, you’ve accumulated a couple of thousand of the little guys.


You can’t see them because they’re only about a third of a millimeter long and are see-through.  (If you are just about to race off and wash your face, it probably won’t help because they get pretty attached to your skin surface!)


You may also have a healthy population of itch mites.  They use their eight legs to burrow into the top layer of your skin to feed in your groin, armpits, between your fingers or toes, or under your belt.
Feeling itchy?


What do they all do?

Some of these non-human cells are beneficial to us.  We all know, for example, that intestinal bacteria, of which there are thousands of different species, interact to help us digest food and promote good health.  Evidence is rapidly accumulating that the nature of your intestinal flora can greatly affect your susceptibility to other illnesses and disorders.


Others, such as the bugs that live on our skin, afford us some protection against bad microbes establishing themselves. When this defense breaks down, we end up with infections, fungal rashes, or itching.


Even the face mites are nothing to worry about. All they want is to eat dead skin cells and a bit of the oil that comes with them.


Some of the bugs on or in us don’t really serve any purpose, but they don’t do us any harm.  They are just hitchhikers whom we feed and provide shelter to without realizing.


In your belly button, for example, it has been estimated that there are thousands of different species.  If you have an ‘innie’ design, you have a greater number and diversity of bugs than people with ‘outies’ who generally only have a few species.


We don’t even know about all these hitchhikers unless something goes wrong or we do not ‘keep their populations in check.’


Underarm bacteria that reside in this wonderfully warm and moist environment just hang around unnoticed until the odours they produce get out of hand and we start to smell, well, ‘off’!


Human Cells:

So now that I have got you all itching and sniffing under your arms, what about the human cells?


A standard reference man – 70 kilograms, 20-30 years old, and 1.7 meters tall will have, on average, around 30 trillion human cells.
Of all the human cells in the body, red blood cells make up around 80%, and other cells around 10%, leaving less than 10% for muscle cells.


By weight, it is a different story; approximately 45% of body mass is muscle cells, 29% are red blood cells, and 27% are all other types of cells.


The Myth is Broken

The claim that less than half our body comprises human cells is busted; it is a myth.  It is more likely that it is a 50:50 split in a healthy human.  The original estimation was done back in 1972, and a lot more is known these days, estimation techniques are a lot more sophisticated.


All numbers are estimations. No one sits down and counts all these cells; it is impossible.


Cells constantly die and generate, and bacterial cells from their intestines are constantly removed. So, play it safe and tell people it is roughly 1:1.


Hope to see you back. Don’t miss out. Stay subscribed and add your thoughts or any comments you have (especially if you have something nice to say!) on the social media links (Linked In or Facebook).


Till next time,


[Copyright The Compliance Concierge 2024]

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Calvin London

Calvin runs a boutique consulting company. He is an established author of over 50 publications but started this site to explore the lighter side of life and all the curious things it has to offer. He is developing a career as a freelance writer.