Slashdot Mirror
Are Human Beings Organisms Or Living Ecosystems?
Hugh Pickens writes "Every human body harbors about 100 trillion bacterial cells, outnumbering human cells 10 to one. There's been a growing consensus among scientists that bacteria are not simply random squatters, but organized communities that evolve with us and are passed down from generation to generation. 'Human beings are not really individuals; they're communities of organisms,' says microbiologist Margaret McFall-Ngai. 'This could be the basis of a whole new way of looking at disease.' Recently, for example, evidence has surfaced that obesity may well include a microbial component. Jeffrey Gordon's lab at the Washington University School of Medicine in St. Louis published findings that lean and obese twins — whether identical or fraternal — harbor strikingly different bacterial communities that are not just helping to process food directly; they actually influence whether that energy is ultimately stored as fat in the body. Last year, the National Institutes of Health launched the Human Microbiome Project to characterize the role of microbes in the human body, a formal recognition of bacteria's far-reaching influence, including their contributions to human health and certain illnesses. William Karasov, a physiologist and ecologist at University of Wisconsin-Madison, believes that the consequences of this new approach will be profound. 'We've all been trained to think of ourselves as human,' says Karasov, adding that bacteria have usually been considered only as the source of infections, or as something benign living in the body. Now, Karasov says, it appears 'we are so interconnected with our microbes that anything studied before could have a microbial component that we hadn't thought about.'"
So the bacteria in the twins is different... why is it worded in such a way as to imply the different bacteria is the reason that one is obese and the other isn't, instead of the type of bacteria changed because being obese (and the eating that goes along with it) favor one type over the other.
Let me remind everyone that microbiologists are almost a different species (if we were organisms). I suppose, in this case, they could also be likened to a different planet.
My dad's long been preaching to me about the benefits of eating yogurt to add back in good bacteria, especially after being on an antibiotic regimen.
The musings of just another geek and his junk.
A recent program on NatGeo (Explorer?) hypothesizes that viruses are also a key part of human evolution.
The "junk DNA" that we all have is likely the result of viruses.
They've also discovered that viruses in the wild actually quite easily jump from species to species, too.
In one of the experiments, they found a large amount of a certain virus in the womb of a sheep during pregnancy. When inoculated against the virus, the pregnancy would not complete.
Very interesting theory.
A billion or so years ago the forerunners of multicellular life made a devils pack with oxygen burning mitochrondia, thereby increasing their metabolic energy an order of magnitude over less powerful energy subsystems like lactosis and sulfur oxidation. This basically created animals with the power of locomotion. So I sometimes visualize a shadow "power body" inside my primary body of these teaming mitochrondia generating 90% of my power. This is not dissimular to prana in yoga, chi in daoism and the force in star wars. Not that I'm going to turn blue and start shooting electric bolts out of my fingers any time soon.
Its very difficult to separate out the different kinds of bacteria, identify them visually and cultivate them. Shotgun DNA originated by Craig Venter helps tell how many kinds of different bacteria species there are growing in different parts of the body. There are more kinds than people expected. Different locations of the body, gut, airways, skin creases, etc. have different ecologies.
Shotgun DNA is a "similar, but different approach". They first map every piece of DNA in every microbe (but in pieces). Then they look for a few key sequences somewhat conserved among species, and note minor differences. This distribution of differences gives a count of species and relatives amounts of each. Later on they may connect these to actual microbe types.
Lemon juice is alkalizing in the body, depite that the juice itself is acidic.
I kind of object to the notion that these bacteria are living inside us as if they are parts of our bodies. As I understand it, the great majority are in our guts; most of the remainder are in skin and mucous membranes that are somewhat exposed to the outside.
The gut is not exactly part of the body. Topologically it has often been noted that the human body is like a tube or torus (a doughnut shape). Yes, there are several sphincters and other openings that can close off the gut, starting with the mouth and ending with the anus. But they open sometimes and they do offer passageway between the outside world and the inside. The gut is more like the skin in terms of how the body distinguishes the external world from its internal environment. It patrols its internals rather vigorously and attempts to destroy bacteria. "Outside" bacteria are tolerated, there is no immune system active outside the body.
So there is still a very significant distinction between those cells which are part of our body, and those cells, including these vast numbers of bacteria, that are outside our body. The gut doesn't really count.