Just Bacteria
Almost 99% of the mass of the human body is made up of six elements: oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus. Only about 0.85% is composed of another five elements: potassium, sulfur, sodium, chlorine, and magnesium.
It's often said that the bacteria and other microbes in our body outnumber our own cells by about ten to one. That's a myth that should be forgotten, say researchers. The ratio between resident microbes and human cells is more likely to be one-to-one.
Because of their small size, however, microorganisms make up only about 1 to 3 percent of the body's mass (in a 200-pound adult, that's 2 to 6 pounds of bacteria), but play a vital role in human health.
Six spots on our body that hide the most bacteria are these moist areas such as the navel (belly button), underarms, groin area, top of our buttocks, the sole of the foot, behind the knees and inner elbows.
About 100 to 200 species may live in them at any given time. Individuals that practice oral hygiene have 1,000 to 100,000 bacteria living on each tooth surface, while less clean mouths can have between 100 million and 1 billion bacteria on each tooth.
Oral mucosa heals faster than skin, suggesting that saliva may have properties that aid wound healing. Saliva contains cell-derived tissue factor, and many compounds that are antibacterial or promote healing. ... The enzymes lysozyme and peroxidase, defensins, cystatins and an antibody, IgA, are all antibacterial.
Human beings are a very complicated form of bacteria. If you look at the earth as a living organism, and who's to say that it's not some sort of super organism? It's certainly a host for life, and we're considered a living organism, and we're a host for life.
There's more Escherichia coli (E. coli) bacteria living inside our gut than there have ever been humans on this earth. There's bacteria constantly around us, and our body is fighting off that bacteria, until our body grows old and dies, and then it doesn't fight anymore. That bacteria then just eats our body. That's what its there for.
If you look at us subjectively and the way we've always been, it doesn't matter how much access to info we have, it doesn't matter how much technological innovation we have, we're always going to destroy the Earth, 'cos, one way or another, that's what we're supposed to do.
Comparing us or someone to bacteria might not be nice but it’s not far from the truth, as scientists now say they have four of our five senses. Bacteria are like humans, they can smell, taste, see and feel. The only sense missing is hearing. The next step is to identify the nose or sensor that does the ‘smelling’.
More than half of our body is not human, say scientists. Human cells make up only 43% of the body's total cell count. The rest are microscopic colonists.
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 our health," says Prof. Ruth Ley, Director, Department of Microbiome Science and Department of Molecular Biology and Genetics at Cornell University. No matter how well we wash, nearly every nook and cranny of our 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.
Max Planck Institute for the Science of Human History affirms: "your body isn't just you".
Prof. Rob Knight, from University of California San Diego, told the BBC: "You're more microbe than you are human." the current estimate is you're about 43% human if you're counting up all the cells," he says.
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, microbiologist at the California Institute of Technology (Caltech) in Los Angeles, 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.
Antibiotics and vaccines have been the weapons unleashed against the likes of smallpox, Mycobacterium tuberculosis or MRSA. That's been a good thing and has saved large numbers of lives. But some researchers are concerned that our assault on the bad guys has done untold damage to our "good bacteria".
Prof. Ley said: "We have over the past 50 years done a terrific job of eliminating infectious disease. "But we have seen an enormous and terrifying increase in autoimmune disease and in allergy. "Where work on the microbiome comes in is seeing how changes in the microbiome, that happened as a result of the success we've had fighting pathogens, have now contributed to a whole new set of diseases that we have to deal with."
The microbiome is also being linked to diseases including inflammatory bowel disease, Parkinson's, whether cancer drugs work and even depression and autism. Obesity is another example. Family history and lifestyle choices clearly play a role, but what about your gut microbes?
This is where it might get confusing. A diet of burgers and chocolate will affect both our risk of obesity and the type of microbes that grow in your digestive tract. So how do we know if it is a bad mix of bacteria metabolizing our food in such a way, that contributes to obesity?
Prof. Knight has performed experiments on mice that were born in the most sanitized world imaginable. Their entire existence is completely free of microbes. He says: "We were able to show that if you take lean and obese humans and take their faeces and transplant the bacteria into mice you can make the mouse thinner or fatter depending on whose microbiome it got."
Topping up obese with lean bacteria also helped the mice lose weight. "This is pretty amazing right, but the question now is will this be translatable to humans" This is the big hope for the field, that microbes could be a new form of medicine. It is known as using "bugs as drugs".
Dr. Trevor Lawley at the Wellcome Trust Sanger Institute, where he is trying to grow the whole microbiome from healthy patients and those who are ill states: "In a diseased state there could be bugs missing, for example, the concept is to reintroduce those."
Dr. Lawley says: "There's growing evidence that repairing someone's microbiome can actually lead to remission in diseases such as ulcerative colitis, a type of inflammatory bowel disease."
He adds: "I think for a lot of diseases we study it's going to be defined mixtures of bugs, maybe 10 or 15 that are going into a patient." Microbial medicine is in its early stages, but some researchers think that monitoring our microbiome will soon become a daily event that provides a brown goldmine of information about our health.
Prof. Knight said: "It's incredible to think each teaspoon of your stool contains more data in the DNA of those microbes than it would take literally a tonne of DVDs to store." At the moment every time you're taking one of those data dumps as it were, you're just flushing that information away. "Part of our vision is, in the not too distant future, where as soon as you flush it'll do some kind of instant read-out and tells you are you going in a good direction or a bad direction. "That is going to be really transformative."
Food in a way for thought!