There are billions of microscopic creatures that live on you. The New York University School of Medicine identified more than 240 distinct microbes on the forearms of six healthy people. Each person’s “wardrobe” of germs seems to be as unique as his or her sense of style…These are on your skin. But you have lots of intimate microscopic companions inside your body. There are armies of microbes in your digestive tract which are so essential to your survival that you might consider yourself a super-organism—human plus microbes equals you. All of them squabbling and eating and defecating and chattering. Think of yourself as a shell that holds the real people together…
Bhagwan Rajneesh / Osho once said that a human’s word could not be relied on because his body was not occupied by a single person but a committee and every ten minutes the committee changed its mind on what it thought or wanted to do. I agree with him. And go one step further. It’s not just different people that inhabit the human mind. Hundreds of different species of animals make up the human body.
In the Belly Button Biodiversity project at the North Carolina State University, a team of scientists studied the contents of 60 human navels in 2011. It turned out that they look like rain forests. They found 2,368 bacterial species, 1,458 of which may be new to science. Some belly buttons had 29 species and some 107. One person harboured a bacterium that had previously been found only in soil fromJapan—where he has never been. Another hosted two species that typically thrive in ice caps and thermal vents. Another area that brims with different species is the underarm. Human skin is like a desert says Julia Segre of the National Human Genome Research Institute in Maryland doing the underarm study. “But as you walk through, you encounter an oasis, which is the inside of your nose,” she said. “You encounter a stream, which is a moist crease.” The team found 18 different groups of animals / bacteria dwelling in 20 different skin habitats. For instance, bacteria live in naturally oily regions, such as the outside of the nose, and feed on the skin’s fats.
There are billions of microscopic creatures that live on you. The New York University School of Medicine identified more than 240 distinct microbes on the forearms of six healthy people. Each person’s “wardrobe” of germs seems to be as unique as his or her sense of style. No two volunteers had all the same microbes on their flesh, though they did have some overlap. The microbes changed as people changed what they used or wore but the number of flora is consistent. “Flora” is microbiologists’ term for microscopic life forms. The study identified 182 distinct species, some of which are new to science. Eight to ten months later they retested four subjects and found 65 additional species.
These are on your skin. But you have lots of intimate microscopic companions inside your body. There are armies of microbes in your digestive tract which are so essential to your survival that you might consider yourself a super-organism—human plus microbes equals you. All of them squabbling and eating and defecating and chattering. Think of yourself as a shell that holds the real people together. Why real ? Because you cannot do without them. These hordes of “gut bugs” perform digestive duties that the human body cannot. They help us ferment our food, produce vitamins for us, and break down toxic chemicals.
The bacteria primarily cling to the intestinal walls. They hitch rides on chunks of undigested food. According to Dr Jeffrey Gordon of the School of Medicine at Washington University, “It’s a whole planet down there. We are never alone. Our partners, who are sentient beings that live within us, are essential to our survival.”
Do you control the gut bugs or do they control you? When you want to eat, it is not “your” appetite that is telling you, but the collective mind of so many foreign residents.
Populations of microbes (such as bacteria and yeasts) inhabit the skin and mucosa. If microbe numbers grow beyond their typical ranges, or if they travel to a-typical areas of the body, disease can result. In 2012, 200 researchers from 80 research institutions comprising the Human Microbiome Project Consortium identified and catalogued the thousands of microorganisms co-existing with humans.
Healthy individuals were found to host thousands of bacterial types, different body sites having their own distinctive communities. Skin and vaginal sites showed smaller diversity than the mouth and gut. Bacteria of the same species found throughout the mouth, are of multiple subtypes and inhabit distinctly different locations in the mouth.
It is estimated that 500 to 1000 species of bacteria live in the human gut and a roughly similar number on the skin. The average human body, consisting of about ten trillion cells, has about ten times that number of microorganisms in the gut. The metabolic activity performed by these bacteria is equal to that of a virtual organ, leading to gut bacteria being termed a “forgotten” organ.
Bacterial cells are much smaller than human cells, and there are at least ten times as many bacteria as human cells in the body. Archaea, primitive living single-celled organisms, similar in size to bacteria but different in molecular organisation, are present in the human gut. Fungi and yeasts are present in the human gut and skin where they consume oils secreted from the sebaceous glands. A small number of bacteria are present in the conjunctiva, which is washed away with blinking and the moisture of the lachrymal glands. Research suggests that the relationship between the species in our guts and humans is not merely commensal (a non-harmful coexistence), but a mutualistic, symbiotic relationship. From head to toe, your body is a veritable jungle of flora and fauna. Some are visitors, some are permanent residents. For thousands of years, these animals have called our bodies “home” — or at least “food.” From bed bugs to eyelash mites, a jungle of insects and arachnids thrives on and around the human.
Then are the visitors that are invented only to live on the human body. The head louse, Pediculus humanus capitis, lives on the human scalp and nowhere else. The human body louse, Pediculus humanus humanus, looks a lot like the human head louse, but it lays its eggs in the seams of clothing, not on hair shafts. The eyelash mites live in and around human eyelashes and eyebrow follicles, where they make their meals from oil and dead skin cells. They look like tiny cockroaches. At night, the mites may emerge from the follicle and wriggle across your face as fast as their eight legs will take them—about an inch per hour. Almost every adult human harbours them. The mites have tiny claws, and needle-like mouthparts for eating skin cells. Almost nothing gets them out. If you use eyeliner and mascara, you most definitely have more of them! Ticks and bedbugs feed on the blood of mammals. The human botfly lives in the mosquito’s body and is delivered into ours through a bite. The botfly larvae burrow into the skin and begin to feed on the host’s tissue. A larva will stick around for a month or two before emerging. The scabies mite, arachnids of the spider family, eats human skin. Living in burrows just beneath the surface of the skin, scabies mites cause itching and rash.
Viruses like herpes simplex may loiter for years inside nerve cells. Causing surface membranes to erupt in nasty pustules or warts. And don’t forget the worms: tape, round, hook, pin, live for decades within you and flukes that settle in the lungs and liver. We are blissfully oblivious to the microscopic life we carry around with us. Considering what those organisms look like, that may be a good thing. But it also begs the question: how many people are you? And who is making the decisions?