Human cells make up only 43% of the body's total cell count, while the rest are microscopic colonists.
This is maybe an odd thing to put on a good news/reasons for hope blog, but I've also had people tell me that they find this info really, genuinely comforting, so I'm putting it up.
Also, further understanding could do a ton to advance medicine, esp. re: allergies, autoimmune diseases, and depression. You can read more about this at the link.
"More than half of your body is not human, say scientists.
Human cells make up only 43% of the body's total cell count. The rest are microscopic [co-contributors].
Understanding this hidden half of ourselves - our microbiome - is rapidly transforming understanding of diseases from allergy to Parkinson's.
The field is even asking questions of what it means to be "human" and is leading to new innovative treatments as a result.
"They are essential to your health," says Prof Ruth Ley, the director of the department of microbiome science at the Max Planck Institute, "your body isn't just you."
No matter how well you wash, nearly every nook and cranny of your body is covered in microscopic creatures.
This includes bacteria, viruses, fungi and archaea (organisms originally misclassified as bacteria). The greatest concentration of this microscopic life is in the dark murky depths of our oxygen-deprived bowels.
Prof Rob Knight, from University of California San Diego, told the BBC: "You're more microbe than you are human."
Originally it was thought our cells were outnumbered 10 to one.
"That's been refined much closer to one-to-one, so the current estimate is you're about 43% human if you're counting up all the cells," he says.
But genetically we're even more outgunned.
The human genome - the full set of genetic instructions for a human being - is made up of 20,000 instructions called genes.
But add all the genes in our microbiome together and the figure comes out between two and 20 million microbial genes.
Prof Sarkis Mazmanian, a microbiologist from Caltech, argues: "We don't have just one genome, the genes of our microbiome present essentially a second genome which augment the activity of our own.
"What makes us human is, in my opinion, the combination of our own DNA, plus the DNA of our gut microbes."
It would be naive to think we carry around so much microbial material without it interacting or having any effect on our bodies at all.
Science is rapidly uncovering the role the microbiome plays in digestion, regulating the immune system, protecting against disease and manufacturing vital vitamins.
Prof Knight said: "We're finding ways that these tiny creatures totally transform our health in ways we never imagined until recently."
It is a new way of thinking about the microbial world. To date, our relationship with microbes has largely been one of warfare.
I promise I’m working on my actual serious fanart but I got reminded of this shitty Simon I made before I watched the movie because this is what all the fanart looked like to me (affectionately)
