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

[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

[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

[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

[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.

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.

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

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: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: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: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!