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.'"

Comments

Obesity & Bacteria

[plague3106]

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.

Re:Obesity & Bacteria

[3p1ph4ny]

I'm not an obesity apologist (or at least, I don't think I am), but I think it's important to recognize that not everyone who is obese just eats cheeseburgers all day. In fact, my diet is pretty piss poor, but I'm thin. Similarly, I know obese vegetarians.

Re:Obesity & Bacteria

[Anonymous Coward]

I've been struggling with obesity for some time now. I eat more healthy than many of my slimmer friends and I often work out more, yet I still weigh considerably more.

Does this mean that it's impossible for me to loose weight? No way, I have been exercising more and eating better and I know have been shedding more pounds. It's just frustrating to watch them eat more junk and not work out at all, and remain slim, where as I would balloon :|

Re:Obesity & Bacteria

[ObsessiveMathsFreak]

Absolutely! I for one reject this studies' thinly veiled attack on the hegemony of genetic determinism!

Re:Obesity & Bacteria

[bickerdyke]

It's how much energy you consume vs how much you use which decide if you get fatter, stay the same or thinner.

Not the quality of the food.

10000 kcals of spinach and you will most likely get more fat.
500 kcals from chocolate and you'd lose weight.

Not exactly. It's not how much energy you consume, but how much energy you gain out of it. Given the right ecosystem in your bowels, you might be able to process 100% of that choccolate-energy, but only 10% of that spinach-energy.

Re:Obesity & Bacteria

[Vellmont]

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

IIRC there have been animal studies (mice I think) where changing the intestinal bacteria lead to changes in obesity. I don't have an article cite, but I read about it in Science News about a year ago. So it's not simply a correlation that supports this theory.

Re:Obesity & Bacteria

[digitalunity]

This would explain what was previously thought to be genetic obesity. I'm obese, as are most of my mothers family. My father is skinny and eats terrible food.

I eat very healthy and I exercise about 20-30 minutes a day(bike riding or swimming) and yet I still weigh 172 @ 17% body fat. Obviously for some people eating healthy and exercising isn't enough.

Whether its genetics or microbes, I don't really care. It does bother me though that people in general blame obese people for their weight. Maybe in a lot of cases that negative view is warranted, but probably for a lot of other cases like me, it isn't laziness.

Re:Obesity & Bacteria

[DriedClexler]

I don't know what your point was, but this wouldn't refute genetic determinism; it just says that the genes determining "you" include those of bacteria.

Incidentally, I don't understand what's so new about this insight. I read a book published in 1995, Darwin's Dangerous Idea by Daniel Dennett (a philosopher rather than a biologist so he was only drawing on what was long-established consensus at the time). It described the view of the body as an ecosystem and suggested that human cells were like "altruistic versions of ant cells" since human cells share even more genetic material (100%) with their neighbors.

Re:Obesity & Bacteria

[Kokuyo]

It's how much energy you consume vs how much you use which decide if you get fatter, stay the same or thinner.

That is plain wrong. It is how much energy of the amount you consume is processed that decides whether you're obese.

And I can prove it: When under stress from work, I tend to eat very little. I usually gain weight during that period of time. In contrast, whenever I have a vacation of more than one week where I am indeed relaxing while stuffing my face with food (e.g. Christmas), I usually tend to lose weight.

This phenomenon is not unique either. Studies have been conducted (at reputable universities like Harvard, mind) that came to the conclusion that the amount and type of food is not directly linked to obesity.

Again, for those who understand German I'd recommend "Esst doch endlich normal" by Udo Pollmer.

He has collected many references (with sources mentioned) to studies that show more correlation between levels of cortisol and obesity than fat or sugar.

Since I have made observations that agree with this theory, I tend to agree with it as well.

Also, I don't quite understand your comment about omnivores. Are you saying we are or we are not omnivores?

Re:Obesity & Bacteria

[hrvatska]

Do antibiotics wipe out everything in person's gut, or is there enough left over that people get recolonized with the same set of microbes they had before taking the antibiotics? Also, are the bacteria that might influence weight gain susceptible to common antibiotics that wipe out most other bacteria in the gut? The summary had a link to an article on the fat bacteria, and it contained the following.

"The issue, then was to determine which came first: the fat, or the bacteria. To find out, the lab took mice that had never been exposed to any bacteria, whose guts were totally germ-free. Half of them got bacteria taken from skinny mice. The other half got bacteria from fat mice."

"Both groups put on body fat. But the mice that received bacteria from obese donors gained more fat over the course of the experiment."

Re:Obesity & Bacteria

[Red Flayer]

Do antibiotics wipe out everything in person's gut, or is there enough left over that people get recolonized with the same set of microbes they had before taking the antibiotics?

I don't recall where I read it, but I distinctly remember reading something along the lines that the appendix serves as a resevoir of gut bacteria, and that it replenishes normal gut bacteria after episodes of horrific diarrhea, for example.

I don't know if the appendix is sufficiently protected from antibiotic dispersion in the gut to be effective after a course of antibiotics. I do know that, for me, taking probiotic supplements after a course of antibiotics helps me return to regular. I'm on antibiotics frequently due to Lyme Disease.

One more note -- I'm not skinny. At all. Though I'm fairly fit (can run 3 miles in 21 minutes).

Re:Obesity & Bacteria

[Pjerky]

Your post is highly misleading and presumptuous. First of all there is a lot more to it than eat X amount of calories and you will lose weight. Physical activity, of course, plays a role. But then there is also the chemical and metabolic response of the body that also has a tremendous influence as well as timing of when you eat, when you go to bed, how much sleep you get, the chemical effects of the food you eat on your body, and a whole host of other things.

Let me give you an example. Right after most people eat their heart rate and metabolic response drops, often they feel a bit less energetic and alert, and their body switches "modes" in how it burns energy, usually burning less and storing more at this point. However my body is different. When I eat my heart rate and metabolic response increases by anywhere from 20 beats per minute to 60 bpm. I get warmer, become more alert and more energized.

During that period immediately following eating I can usually exercise longer than other times and not feel tired at all. But ironically this doesn't mean that I am skinny. In fact I am obese. My body stores energy from everything and is VERY efficient at squeezing every last bit of energy and nutrition out of food. My best friend by contrast is skinny and would collapse if he at the same amount of calories that I do (I currently average between 1500 - 2000 calories a day). He has to eat at least twice as much as I do just to function. His digestive system is highly inefficient and his heart rate and metabolic response drops off after eating.

Now another thing that research has shown is that if you spread out your calories across 5 meals in a day you will burn more calories and store less than when eating the same number of calories in 3 or less meals in a day. This technique is used by many to help them lose weight to great effect.

So giving some blanket statements about getting fat or thin just don't apply. It really varies from person to person as to what things effect what people.

Re:Obesity & Bacteria

[NotQuiteReal]

Hmmm, maybe you could come up with a pill, using phage therapy to kill the "fat bacteria", IF you could identify both the bacteria and matching phage(s)...

Random thought - I was just reading about the efficacy of phage therapy for wounds that were not responding to antibiotics.

Re:Obesity & Bacteria

[Gilmoure]

Ah, an investment banker. Your ideas are intriguing to me and I wish to subscribe to your newsletter.

Re:Obesity & Bacteria

[Poltras]

I know a guy who just stop eating. After a year, he doesn't weight anything, and he doesn't have to move anymore! Quite impressive.

Re:Obesity & Bacteria

[plague3106]

Your post is rich. Yes, your body is so unique that it does the opposite of what everyone else does. And of course your body is much more efficient. I love the excuses as to why you're overweight.

Let me hit you with a clue stick; yes, certain things such as timing does matter. However, at the end of the day, if your intake greatly outstripes your expendature, you WILL gain weight. You can space your meals all you want (and really should be), but it won't make up for the intake problem.

Here's my take on your post. Either you are eating 1500 calories a day, which means your lean body weight should be about 136 (really small for the average male), or, as I suspect... your lean body weight is higher, and you're putting your body into starvation mode. So it stores as much as possible. The other alternative is you really have no idea how much you're eating, and are consuming much much more. So... do you know your % of body fat, and are you actually measuring out your food (and being honest?) Right now, I'm leaning toward the latter... why? Well, lets move on..

The likely reason your BPM goes up after eating is that you're eating crap. Lots of simple carbs; white pasta, white bread, white potatoes, some kind of caffinated drink. The simple sugars give you a rush... but also a crash later (unless you follow up with more junk).

As for exercising goes... yes, eating before you exercise puts energy into your blood. That's why when I body build I get complex carbs and protein at least 30 minutes before a workout. That is the point of eating, after all, is to get energy to keep living. It'd be suprising if you ate and got more and more run down. I wouldn't advise eating less than 30 minutes before though.. your heart rate nonsense aside, if you are digesting your blood vessels around your gut dialate to pick up nutrients and remove waste (and provide energy for digestion), which means blood vessels around your muscles must constrict. So you're not going to get as much from your workout.

In all seriousness though... you're not unique, and I bet if you talked to a personal trainer and HONESTLY measured and tracked what you're eating, you'd be able to change (if that's what you want).

Re:Obesity & Bacteria

[nine-times]

Right. Frankly, I'm tired of people clinging to the old wives tale that it's a simple equation of [number of calories in food eaten] - [number of calories expended in exercise] = [number of calories stored as fat]. It sounds nice, and gives you all the reason you want to hate on the fatties, but it flies in the face of lots of good science.

Just to stay really basic, we know that some food takes more work to digest than others. But even ignoring that, it's been shown pretty conclusively (and you'll notice if you just look around) that two different people on the same diet and exercise regiment can have different body mass indexes. Two people can just process food differently. Given a diet of X calories, one person's body might naturally produce more muscle, while another produces fat, and a third person might seem to just shed those calories completely. There has been some research that suggests that it's possible for your body to basically choose not to hold on to excess calories.

It's even pretty clear that the same person's body can react differently to essentially the same diet and exercise. High stress levels and sleep deprivation can cause your body to respond differently to the same intake. Hormone levels can make a big difference. And yes, I've read about a few different studies that suggest that the bacteria in your gut that helps you digest the food can have an impact.

Of course having a good diet and exercising regularly has an impact on your weight and overall health. However, there's a lot more involved.

Re:Obesity & Bacteria

[Stradivarius]

Newton's laws of gravity are not really right either. They didn't know about relativity back then. But Newton's laws are are good enough approximations for things ordinary people are doing in their day.

Same thing goes for how to lose weight or avoid being fat. Eating fewer calories and burning more calories by exercising isn't the complete picture. Some folks have genetic predispositions for either high or low metabolisms. Some build muscle easier than others. And now we find out that some folks have different microbial components that can influence this.

But none of that changes the basic advice you should give people, which is if you want to be fit (or at least not fat), then eat right and exercise regularly.

This isn't "hating on the fatties". If you let people incorrectly believe that "my genes made me fat", while it may make some folks feel less guilty, it also undermines their confidence in their own ability to get healthy. It's in nobody's interest to make fat people feel like being fat is just their lot in life, rather than an obstacle they could overcome with hard work and persistence.

Re:Obesity & Bacteria

[Have Brain Will Rent]

It is true that body weight is a very complex issue an different people will face different challenges. None of that, including the fact that one person may extract more usable calories from the same food intake as another person, negates the fact that if your total intake is X calories and you burn X+1 calories then you will lose weight.

Re:Obesity & Bacteria

[ConceptJunkie]

But it's healthier energy! ;-)

Re:Obesity & Bacteria

[Calithulu]

Oh, I don't know. I've observed bacteria directly through a microscope. Granted, it has only been around for hundreds of years, but I don't consider it a "mystical tool".

Additionally, I have seen the effects of bacteria, as witnessed through a microscope that would reasonably allow me to come to the conclusion, without claiming "magic", that they do influence the hosts and environments in which they live.

Demons, on the other hand, I can't witness since I can't go to Hell and observe them in their supposedly natural environment. I can't witness them corrupting the youth or taking the form of serpents and offering apples to young women not wearing much.

I see your point, that some things ascribed to demons from ancient times were really bacteria. However, I don't see the point of observing that. We know that already, which is why we don't ascribe demons to anything outside of religious or mythical realms anymore.

Of course

[Kell Bengal]

Both, of course. Why can't we be an eco system that is also a self-contained individual? Arguably, we could say the same thing about Earth itself (guess who's cancer?)

Re:Of course

[Sique]

As in the old jokes, where two planets meet:

- How's going?
- Bad... I got Mankind.
- Had it also. Not a big problem though, it goes away.

Let me be first

[Fotograf]

as a human overlord to welcome our bacteria inhabitants

Not just "bacteria"

[erroneus]

Perhaps these are the midicloriens we have been looking for. Try to speak to them with your mind and see if you can make things move... (it only works for me in the bathroom when my concentration is at its highest and the accoustics are at their best)

Also, this brings another question to mind as well. Have our snooty English teachers been correct in using "we" in weird places? "How are we feeling today? Did we do our homework?" The ramifications are... spooky.

Finally, let's tell ALL the germaphobes out there! This hand-washing nut-cases are annoying! We can either break them of their phobias or finally kill them. Either way, their irrational fears will bug me no further. ("Clean" has it's place, but primarily when it has to do with food and equipment!)

Its a stupid distinction

[DarkOx]

While the study of our relationship with the bacteria and other microbes that live inside us is interesting and valid its kinda dumb to talk about ourselves as ecosystems. We are another life form, that has a symbiotic relationship with those microbes in a larger ecosystem.

We don't need words like symbiotic if we are going to think of ourselves as an ecosystem. Also just about any animal or plant made of more than a few cells is going to be an ecosystem under this implied definition. I am not sure how exactly we want to define ecosystem but something a little more complex than "any thing which something lives inside" seems appropriate.

Applies to brain cells as well?

[Anonymous Coward]

This must be why I hear those voices in my head.

"Eat that donut"
"Don't eat it!"
"Eat it!"
"I am bored"
"Natalie Portman"

I am joking.. or am I?

Re:Applies to brain cells as well?

[bickerdyke]

9 out of ten voices in my head tel me that I'm not insane.

The 10th just keeps on humming the Tetris-tune...

Made of cake

[TheMonkeyhouse]

did you see that this is all based around an obesity study? this has to be the BEST reason-why-i'm-fat yet!

"it's not me, it's the entire living eco-system of which i am comprised. and my DNA. and it's glandular. and i'm big boned."

i think most of the people in the study were made of cake.

Good Germs Bad Germs

[Kieckerjan]

I just read Good Germs Bad Germs by Jessica Snyder Sachs, a fascinating, accessible and up-to-date account of roughly the same subject matter. Will change your view on bacteria forever.

http://www.amazon.com/Good-Germs-Bad-Survival-Bacterial/dp/0809050633

Sounds like "LIves of a Cell" by Lewis Thomas 1978

[elwinc]

You could have read essentially these ideas over 30 years ago in a book called "Lives of a Cell" http://www.amazon.com/Lives-Cell-Notes-Biology-Watcher/dp/0140047433

Yogurt

[mc1138]

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.

radiation

[GregNorc]

Makes sense. I read somewhere that one of the reasons medium/high doses of radiation kill you is all the helpful bacteria in your digestive system are killed, leaving you unable to process nutrients.

Re:radiation

[Just Some Guy]

I read somewhere that one of the reasons medium/high doses of radiation kill you is all the helpful bacteria in your digestive system are killed, leaving you unable to process nutrients.

Well, that and the internal burns, shredded DNA, denatured proteins, and general nastiness that results from your insides being subjected to bursts of concentrated energy.

Viruses, too

[forrie]

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.

Re:Viruses, too

[interkin3tic]

They've also discovered that viruses in the wild actually quite easily jump from species to species, too.

Some do. Rabies appears to infect most mammals, but that's an incredible range for a virus, and there is one virus that can at least tolerate being in a host from a completely different kingdom, don't remember the name of it but it can live in aphids and some plant species (also not sure which one it prefers). As I understand it, most viruses seem to stay within their host species though, it's typically a very lucrative niche. I'd guess it depends on the specific virus, some because of their mechanisms are probably more able to jump to certain species than others.

Re:Viruses, too

[forrie]

From what I recall of the program, a series of blood tests were performed on a range of dead animals found in the jungle (somewhere in Africa).

A comparative study was performed with blood samples from the local tribes people. It's there they discovered a multitude of viruses that would otherwise have been assumed animal specific.

Here is a link which I believe is the episode: Explorer

The concept is rather frightening, if you think about it.

I view myself

[Centurix]

As a series of tubes.

Re:Point of view

[sakdoctor]

Consider a spherical human...

Are we living ecosystems?

[Ukab the Great]

Or are we dancer?

Re:Are we living ecosystems?

[newcastlejon]

This makes me wish for an "-1 Over-played, Over-rated tripe of a song" mod point.

Re:Body is the Vessel for the Soul

[fuzzyfuzzyfungus]

"2. alkalinity (such as drinking lemon juice in water)"

pH fail. (or "pHail" as the cool kids are saying these days)

Re:So: too much cleaning is bad

[CheeseTroll]

Given a few years after installation, carpets are an entire ecosystem, themselves!

Re:Body is the Vessel for the Soul

[seven of five]

2. alkalinity (such as drinking lemon juice in water)

I see sleeping through fourth-grade science's done wonders for you...

Re:Star Trek...

[sukotto]

No, it was a Futurama episode in season 3

http://en.wikipedia.org/wiki/Parasites_Lost

Entertaining related TED talk

[Wolfbone]

Humans (just) human idea also referred to by Bonnie Bassler in excellent talk here:

http://www.ted.com/index.php/talks/bonnie_bassler_on_how_bacteria_communicate.html

Re:So: too much cleaning is bad

[Lumpy]

Just the excuse that I have been looking for to avoid having to hoover the carpets!

Is that what women are calling taking a bath nowdays?

Re:Head, shoulders knees and toes

[Inda]

Man walks into the doctors

-- Doctor, I can't stop sneezing!

-- You have the Sneazles, said the doctor, after having a quick look.

-- What about my bad feet?

-- A common case of Toelio, said the dismissive doctor.

The man dropped his pants

-- and this?

-- Ah, the doctor exclaimed, the Smallcox!

100 trillion mitochrondia too

[peter303]

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.

DNA shot gun analysis is a powerful analysis tool

[peter303]

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.

Re:WTF. Why is this any kind of breakthrough?

[KeithJM]

Alternative medicine has been aware of this fact (that the microorganisms that live in our bodies are a normal part of our physiology) for ages.

First, modern medicine has been "aware" that they were there and had beneficial effects for decades also. There are two things you're missing:
1. The discovery is not that they help digest food and nutrients, but they might help determine how your body uses it
2. The difference between "aware of this fact" and actually doing a reproducible study to help determine whether this "fact" is true.

My only real problem with alternative medicine is that it doesn't care what is true, just what we believe to be true.

Re:Body is the Vessel for the Soul

[Anonymous Coward]

Lemon juice is alkalizing in the body, depite that the juice itself is acidic.

After reading this

[kenp2002]

After reading through this I can no longer tolerate a sanctioned policy of genocide against an indiginous life form. Thus all bacteria and viruses must be protected like any other form of life. In our own personal ecosystem the use of weapons of mass destruction against said bacteria and viruses must stop! Save the bacteria, whales, dolphins, etc.) As delicate as the ecosystem is we must prevent mass extinction and stop polluting the ecosystem with toxic medication and antibiotics!

Oh man the Earth worshippers are gonna run with this one... Gaia has a disease...

How long till the last shread of reason is lost? Humans are machines, nothing more made up of lots of parts. You are just as worthless as a laser printer because you are no different. There is no free will, just complex biochemical reactions guided by DNA and environment. No love, just an interaction of mating protocols, chemistry, and complex algorithms running in your advanced CPU. YOu illusion of conciousness is noting more then a product of random sequences of programs surviving the evolutionary tread mill.

Scifi got it wrong, the machines do take over, we mearly give up and turn into machines... No wonder the more "advanced" we get, the cheaper life becomes and the more we treat one another like machines...

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[account_deleted]

Comment removed based on user account deletion

Re: Point of view

[DrProton]

Bacteria are prokaryotic. Human cells are eukaryotic. So we're a colony of mostly prokaryotes, if we're just counting cells. The eukaryotic human cells win the total mass race, however.

Ah, Microbes!

[YoyodynePropulsionIn]

They live inside us, so can they influence our decision-making ?!#?

There seems to be at least one scientist that believes so. Dr. Jaroslav Flegr from Prague Charles University (founded in 1348 is one of the oldest universities in the world and nowadays is one of the most eminent educational and scientific establishments in the Czech Republic) published some mind-blowing discoveries.

Dr. Flegr's claim is a simple one. Microbes influence YOUR decision-making.

You will find the presentation here http://www.natur.cuni.cz/~flegr/toxo_slides/index.php

If you dare to reach slide 14 you will learn that:
"The infected women had higher affectothymia, which means, they were more warm-hearted, outgoing, easygoing. They had also higher superego strength, which means, they were more conscientious, persistent, moralistic, staid. Both men and women had higher guilt proneness."

Now, why this is not a mainstream science I do not know. But I will leave it for you to decide.

You can research that or you can go to flickr.com and type "Empire Builder" in the search box and see some really cool photos.

The choice is yours...
(or is it?)

Parasite Rex

[proggoddess]

This is a great book about how free-living organisms (like ourselves) have evolved alongside parasitic organisms (like bacteria). I found it interesting that the scientists that the author interviewed all look at free-living organisms not as individuals, but as miniature eco-systems for parasites. Several scientists said "I don't see a mouse (or frog, or fish) anymore, I see a bag of parasites." A little gruesome, but true. http://www.amazon.com/Parasite-Rex-Bizarre-Dangerous-Creatures/dp/074320011X/ref=pd_bbs_sr_1?ie=UTF8&s=books&qid=1239818586&sr=8-1

Solution to Obesity

[relguj9]

Make out with skinny chicks.

Custom Gut Ecology

[psydeshow]

So where is the pricey SoHo boutique I can go to to be cleaned out and re-populated with an exclusive culture grown by Natalie Portman?

I know the economy is bad, but the bio venture capitalists are really slipping if this isn't an option by now.

Re:Custom Gut Ecology

[psydeshow]

"One visit, and now I walk around with a shit-eating grin."

Not so much living IN humans as living ON them

[SiliconEntity]

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.