Sewage Bacteria Reveal Cities' Obesity Rates

benonemusic writes A new frontier in data mining: Researchers at the University of Wisconsin-Milwaukee and the Marine Biological Laboratory in Woods Hole, Massachusetts surveyed bacteria from human waste in the municipal sewage systems. Surprisingly they found different proportions of bacterial species in cities that correlated with obesity rates in those municipal areas. The researchers believe that these bacterial samples can yield city-level information on other diseases as well. Hopefully this isn't just a messy case of spurious correlation.

Comments

Gut flora

[flaming error]

Health problems, including obesity, may be caused by what's in (or missing from) gut bacteria.

Re:Gut flora

[gewalker]

Yes, but if you want to know how obese a city is you now have a new choice. A) Analyze at remains from the sewer B) Analyze photos from Facebook or C) Spend 5 minutes at the local Walmart.

Re:Gut flora

[beelsebob]

The news here for me isn't "here's a way to analyse a city's obesity rate", it's just yet another piece of evidence for "obesity is caused primarily by gut fauna". This would seem to add up with the obese population's assertion that losing weight is incredibly hard, while the non-obese population asserts "just eat less, it's trivially easy". The only way these two assertions can add up is if the two populations have some very different environmental factor going on. Gut fauna making obese people absorb much more of the energy from their food would seem to add up as just that kind of environmental factor.

Re:Gut flora

[Anonymous Coward]

I agree, but, perhaps what a person eats shapes their gut fuana to best digest their diet. If you spend years eating only twinkies and ho-hos...

Re:Gut flora

[Anonymous Coward]

Health problems, including obesity, may be caused by what's in (or missing from) gut bacteria.

Sorry, no. Obesity is not caused by bacteria (or genetics, or "conditions"). Obesity is caused by consuming more energy than you actually use. Hunger queues may be affected by bacteria, but those are something you can adjust to. The actual weight gain, however, is nothing more complicated than eating more than you need to sustain your body.

Honestly, how a site full of self-professed science geeks keeps ignoring basic thermodynamics continues to blow my mind...

Re:Gut flora

[Anonymous Coward]

If you put on weight, you eat more than _your_ body needs. The amount of calories needed depends on your body and your activity level. Someone who runs around all day and takes the stairs and will burn more calories than someone who sits on their butt all day and always uses the elevator.

Don't just monitor your intake, reduce it until you find that point where _your_ body loses weight. That point exists for everyone, go find yours. That might mean you need to eat less than other people if your gut flora is more efficient. If I eat like my body would like me to, I'd be at least 30 pounds heavier. Since I've been there and don't like it, I don't eat that much. In the end It comes down to willpower.

So far all people I have seen trying but unable to lose weight said they don't eat more than others, but if you watch them they do. Here a bit extra, there a larger serving, soda instead of water, a snack during the afternoon... Everytime I ask them to stick to what I eat and match my amount they complain about being hungry and needing something to eat. Well, I feel some hunger to, but I don't act on it. That's where the willpower comes in.

Re:Gut flora

[Opportunist]

Unfortunately the human body is not your average ICE. It doesn't "just" work on basic thermodynamics.

It all starts with the fact that we not only consume "fuel". We actually consume quite a bit of stuff we cannot process. We actually MUST consume that stuff for without we start to get reeeeeally messed up. I dimly remember a NASA experiment where they tried to reduce astronaut food to the nutritious stuff. You know, to eliminate ... erhm ... waste. Guess what: Astronauts still shit. Because it didn't work out. The test people got REALLY sick. Sure, they got all the nutrition they needed, But I guess human can't really work if he doesn't poop.

Which gets to part 2 of the problem: We shit stuff that is still quite nutritious. Ask your local fly population. Our "waste" is not just waste. There's quite a bit of stuff in there that could still be "digested".

In a nutshell, the human body is not the best kind of engine. I'd actually be interested in how good our energy conversion rate is, but I wouldn't be surprised if it is really, really shitty, even compared to the engines we build. And I'm not even talking about us using a good deal of the energy we consume just for heating. I'm talking about the energy we consume that goes out right our exhaust without us actually using it sensibly.

And then there's of course the different metabolisms that will have different effects on different foods. Because 1000 KJ from one food source is by no means the same as 1000 KJ from another. And even the same food eaten by two different people will not be metabolized in the same way to the same efficiency.

Sorry, but the law of thermodynamics alone won't cut it.

Re:Gut flora

[beelsebob]

The point being that "you" doing it may be very different from someone with different gut bacteria doing it. The amount of willpower needed for you to keep your food intake at a suitable level may be fairly high, but still doable. Meanwhile, the level of willpower needed for someone with different gut fauna may be more comparable to sjames' example - beyond that of the typical person.

Re:Gut flora

[cfalcon]

Cool, I got modded troll for speaking the truth. Hell, in high school, two brothers- the fat one ate almost exactly half of what the thin one ate. In his 20s, the thinner brother finally had to start paying attention to what he ate (not literally "twice what a normal person would think a meal is"), but he's definitely not fat to this day. The fat one did weight watchers and other shenanigans, and still struggles to have a reasonably body to this day. Yes, he was eating "more than he needed", but you fucking know what? He's essentially been hungry his whole life, and the "amount of food his body needs" is QUITE clearly an amount that he ends up in constant hunger over.

That's the important part about all this. Did you know that the blood of two normal weight men, one who lost weight YEARS ago, and one who never had any tendency towards fatness, have vastly different levels of the hormones linked to satiety and hunger?

Yes, of course you can lose weight by eating less than your body needs to maintain its current weight. But that's never NOT been the case, and "starve yourself thin" is not why thin people are thin. They aren't starving. That's the point. There's very clearly triggers. Assclowns can mod me -1 all they like- it's very clearly the truth.

What about the study where they tried to get inmates to gain weight by overeating, and none could? If you think it's as simple as food consumed, you're willfully blind to reality (presumably, a reality which benefits you in some way, or at least you believe that to be the case).

Re:Gut flora

[CrimsonAvenger]

This whole business reminds me of the arguments over whether ulcers were caused by stress or bacteria.

Turned out to be that some were caused by the one, and some by the other (about 1/3 of ulcers can be "cured" by taking the appropriate antibiotics).

Maybe, by and by, we'll find that some obesity is caused by the wrong gut bacteria, and some by bad habits.

Disclaimer: I've been moderately overweight. And I've been thin. Never was much trouble going from the one to the other and back.

Re:Gut flora

[ArsonSmith]

I can reach, and maintain, most any weight goal I choose.

Two happy cookies for you. I can as well and I've gone through the effort and dropped over 100lbs and swore I would keep it off for ever, but the gpp poster is right. It felt like I was holding my breath. People would say you look great, doesn't it feel better? I would reply in a normally pissed off state that it felt fucking hungry. I was not happy though kept it well for nearly 5 years. I have now put most of it back on. My mood is generally better though now I have the old stigma of being fat.

Ohh well, life sucks. Sure would be nice if I could find a way to be both happy and fit.

Re:Gut flora

[disambiguated]

TFA says "the microbiome can influence, and be influenced by, a range of characteristics such as weight, disease, diet, exercise, mood and much more." So they acknowledge the causation can go both ways.

But it gets even more interesting. According to a Ted talk I saw about this the other day, there are apparently two different ways that our gut microbes might cause obesity. One is related to what you said:

Which gets to part 2 of the problem: We shit stuff that is still quite nutritious. Ask your local fly population. Our "waste" is not just waste. There's quite a bit of stuff in there that could still be "digested".

From the Ted talk:

When we take the microbes from an obese mouse and transplant them into a genetically normal mouse that's been raised in a bubble with no microbes of its own, it becomes fatter than if it got them from a regular mouse. Why this happens is absolutely amazing, though. Sometimes what's going on is that the microbes are helping them digest food more efficiently from the same diet, so they're taking more energy from their food, but other times, the microbes are actually affecting their behavior. What they're doing is they're eating more than the normal mouse, so they only get fat if we let them eat as much as they want.

So apparently some microbes allow you to extract more energy from your food so you put on more weight for a given amount of calories. But other ones might affect your appetite somehow. There's more in the talk, and it's not just mice: there's research in humans as well.

Re:Gut flora

[Riddler Sensei]

The thing about a statement like this is that, regardless of how correct it may be, it is completely, and flaccidly, useless.

Let's switch the analogy to something like a CPU scheduler.

Say that we have an OS and it habitually lags ass. Tasks quickly begin to accumulate within our OS, CPU utilization drops precipitously, and we eventually hit a deadlock. This is a front and center problem. All of the project's developers have been shuffled into the main hall to address this one issue, because if this doesn't work then we have nothing.

The hall is buzzing with discussion. People are pouring over profiles and usage patterns. Real progress is being made. Then, suddenly, from the back of the hall comes a booming voice.

"It's tasks in, tasks out. We're just taking in more tasks than we're finishing." ...

You'd be able to hear a pin drop. Okay, yes, technically. But...and?

Re:Gut flora

[suutar]

I'm sure that has some effect, although intuitively it seems likely that unless your diet is _really_ weird (I mean you're actively avoiding some element that some strain of flora needs but you don't), any strain of gut flora is going to be able to find enough food in your food to keep afloat. Oral antibiotics, on the other hand, are at their most concentrated when the intestinal flora encounter them, and given what we've already seen in terms of resistant bacteria in the wild, they could easily weaken one strain to a level where other, more resistant strains can take over the territory. And if that other strain is one that converts hard-to-absorb calories (like complex carbs) into easy-to-absorb calories (like sugar), well, suddenly you may be getting a bunch more usable calories from the same amount of food and seeing your weight start climbing when you haven't changed behavior.

Re:Gut flora

[beelsebob]

As for being able to do it. It's a matter of wanting and therefore motivation. That motivation can come from different sources.

That, and exactly what you are being asked to do. If your body absorbs 80% of the glucose in food (thanks to bacteria in your gut that break down starches into glucose), while an average human only consumes 60% (thanks to a lack of those bacteria), you are being asked to eat a significantly smaller amount of food. The result is that even if you have motivation, and more willpower than the other person, you may still not be able to control yourself, as you are being asked to control a greater urge than they are. You are being asked to keep your stomach less full than that less efficient human.

Re:Gut flora

[WillKemp]

Maybe, by and by, we'll find that some obesity is caused by the wrong gut bacteria, and some by bad habits.

Maybe, but i doubt it's as simple as that. I think the dogma that obesity = excess fat is severely confounding our understanding of this issue. One thing i never see discussed anywhere is the contribution to obesity made by fluid retention - which i suspect is considerable.

Everyone seems to assume that excess flesh is fat, but that's not necessarily the case. The body can retain fluid in response to environmental contaminants of various types and most people live in ever more toxic environments. If you seal people into houses with electronic equipment, furnishings, carpets, etc, all of which have been drowned in flame retardants - volatile organic compounds which have been linked to many different health impacts - it seems likely that at least some of them will end up with some degree of fluid retention as a result.

Antibiotics flame retardants, and shit food are probably the three main contributors to obesity. Wrong gut bacteria is one product of antibiotics use.

I'm affraid the data is ...

[Laxator2]

... complete crap.

Sorry, had to say it.

I always thought. . .

[Idou]

That data mining required you to wade through shit, but this is ridiculous. . .

Re:I always thought. . .

[Mr D from 63]

Well, it certainly is a shitload of data to analyze.

There is other evidence

[SuperKendall]

I read a recent story where someone who had a fecal transplant (which affects gut flora) suddenly had a dramatic weight gain as a result.

It seems like that could work the other way also, as a really quick way to get thinner faster...

Re:There is other evidence

[ebrandsberg]

The opposite has also been observed (http://gizmodo.com/the-secret-to-weight-loss-might-be-poop-transplants-fro-1265888152). As someone who is married to someone who has struggled with her weight for all her life, and has done everything including a strict 1000 calorie diet with very little results, I KNOW there is more to it than "just don't eat as much". The people that don't have the issue or haven't lived with it don't understand the issue, and assume that "it is their fault".

Re:There is other evidence

[WillKemp]

As someone who is married to someone who has struggled with her weight for all her life, and has done everything including a strict 1000 calorie diet with very little results, I KNOW there is more to it than "just don't eat as much".

Have you considered the possibility that at least some of the excess weight is fluid rather than fat? The body seems to retain fluid in response to conact with environmental contaminants. In my case (and i'm not really fat), i get fluid retention from breathing in the fumes pumped out by computer cooling fans - presumably mainly flame retardants. It has other effects than just fluid retention (cough, headache, etc) and different computers have different effects - presumably because they use different classes of flame retardants - but the fluid retention is quite noticeable and can happen quickly.

All electronic equipment seems to be drowned in flame retardants before it leaves the factory, as does furniture, carpets, etc. Flame retardants are volatile organic compounds which may also be persistent pollutants, and have been linked to an array of different health impacts. Some have been banned (e.g., polybrominated diphenyl ethers (PBDEs) and dibrominated phenyl ethers (DBEs) - banned by the EU in about 2005) but they just keep replacing them with other ones, which have unknown effects. Brominated flame retardants seem to be being phased out because of health concerns, and replaced with fluorinated ones- which i supect may prove to be worse.I believe brominated flame retardants were developed to replace chlorinated ones - again because of health concerns.

Anyway, i think fluid retention caused by environmental toxins merits investigation to determine its role (if any) in obesity.

mhm

[fisted]

At least that data is pretty much anonymized.

The obivous conclusion

[radarskiy]

If obesity is purely a moral failing, then gut flora must be purely a moral failing too.

Hopefully this isn't just a messy case of spurious

[thegarbz]

Hopefully this isn't just a messy case of spurious correlation.

Good work raising doubt on the link between sewage bacteria and obesity only a month after posting a story on bacteria's role in
weight control. This one seems somewhat obvious to me.

Correlation of antibiotic use and obesity

[si3n4]

major co-incidence today as my PBS station was putting on it's fundraiser series of every diet plan guy in the world. So much fluff to info, but one person was arguing this same viewpoint (gut biota and tendency to be obese) and showed a startling pair of maps - one with the level of antibiotic prescription and the other with the level of obesity. Startling overlap. Google "antibiotic obesity map" Theory being that the use of antibiotics disturbs the balance or microbes and set more of the population up for obesity. Since the idea is that different bacteria feed on different foods this comes back to skipping refined cards and sugars and eating more vegetables - basically the same kind of prescription they all end up with - and trying to skew the population faster with probiotics. On thing I do now is that every thin person out there is not a paragon of good eating and exercise and not every fat person is a pig with their head in the trough. I was never a skinny person but got progressively more massive with age until one doctor finally thought to test my thyroid which was pretty much crapped out. On the synthetic stuff now and slowly morphing back to - well, something thinner.

Re:Correlation of antibiotic use and obesity

[QRDeNameland]

One simple yet undeniable observation that supports the role of antibiotics in obesity: antibiotics fed to livestock reliably fattens the animals. Of all of the environmental changes of the past 40-50 years commonly cited to explain the enormous rise in obesity rates in the Western world, the fact that antibiotics reliably fatten animals make them one of the more plausible factors, in my opinion.

The Real Poop

[fyngyrz]

Sewage Bacteria Reveal Cities' Obesity Rates

No shit?

Re:So, which bacteria are the good ones?

[NetFusion]

There are studies that have shown that it is extremely difficult to change you gut flora by simply ingesting a probiotic pill. What little life makes its way through the hostile environment of the stomach finds a world with very few free niches to colonize and no preferred food sources to live on. The more effect way is to just eat the kinds of foods the life you want to live in your gut thrive on. All life comes covered with the microbes necessary to digest itself and return it to the soil. You are what eats what you eat. If you want to get healthy microbes in your diet, eat non pasteurized fermented foods like sauerkraut.

Re:Can't they just measure sewage volume?

[jc42]

It's my understanding that obese people eat more and therefore produce more poo. Surely this would be easier.

I wonder if this is true. We seem to be seeing claims that different people eating exactly the same food will sometimes lose or gain weight. Strictly controlled studies seem to be in their infancy, but the implication seems to imply the opposite: Some people's digestive systems (gut bacteria and all) effectively turn more of the input into digested "food", leading to weight gain and decrease in fecal output, while others digest less of the input and produce more output. The former store the excess as fat; the latter stay thin or lose weight. There's an implication that "efficient" digestion leads to weight gain and decreased fecal output, while inefficiency produces weight loss and increased fecal output. (Mass is generally conserved, right? ;-)

I suspect that it's actually more complex than that. But most of the comments here do seem to be aimed at blaming people for (presumably intentional) weight gain or loss. For us to say anything with scientific validity, we really should dispense with attempting to place blame, and rather try to document the details of just how the whole process works. Once we have better understanding of the scientific details, maybe we'll be able to give people medical advice that actually helps them reach and stay at whatever weight they'd prefer.

In this case, the summary's snide comment about spurious correlation is probably right on. What is generally believed about weight gain/loss is mostly based on mythology (or marketing ;-), not science, and has been proven wrong so often that it's odd that people even pay attention to claims on the topic any more.