Hacker News new | past | comments | ask | show | jobs | submit login
Pathogen from gut of obese human causes obesity in germfree mice (nature.com)
131 points by not_that_noob on Dec 19, 2012 | hide | past | web | favorite | 129 comments



Gut bacteria are an extremely powerful system within our bodies and are mostly still mysterious to us. Imbalances of one type or another lead to large amounts of bacterial toxins being introduced to the intestine and the bloodstream, with wide-ranging mental and physical effects. I'm not surprised that contribution to obesity is among them.

It works kind of like this:

You eat too much refined/processed food, that is high in sugars of any kind, especially complex polysaccharides and the food is not fully digested by your stomach + small intestine, and ends up in your large intestine. This surplus of sugars provides abundant food to your billions of gut bacteria, and they start to grow out of control, and mutate. Those mutated bacteria now dump their toxic waste by-products into your body.

Following restricted diets that are intended to reduce the food supply to your gut bacteria colonies is a valid and often the only successful way to treat the conditions caused by this influx of bacteria and toxins.

Antibiotics of any kind are simply too broad a weapon - they will attempt to eliminate everything which will result in other imbalances. The food we eat every day is the most important factor for intestinal and therefore overall health...

[1] This book is helpful: http://www.breakingtheviciouscycle.info


Forgive my naivete (I have a passing knowledge about diet), but isn't 'complex polysaccharides' more or less a synonym for 'complex carbohydrates' (excluding oligosaccharides)? I feel that most readily available refined/processed food is low in complex carbs since the processing breaks them down, and because simple carbs are cheaper and taste better.

Essentially my question is this: A fresh vegetarian diet is going to be high in the complex polysaccharides that you mention. So why are vegetarians statistically thinner than the average population, if these complex polysaccharides are wreaking havoc on their digestive systems?

This whole question breaks down if I'm mistaken about the definition of complex polysaccharide. Thanks.


You are correct to doubt the meaning of these words as they are being flung around for the sole reason of providing credibility. Your mistake is coming with scientific thoughts into a discussion that is utterly non-scientific and purely based on making money with buzzword-laden books by turning anything related to food into a weird cult-like experience.

But at least your questions are in an area where I can maybe help out. Carbohydrates are just what the name says: carbon molecules with hydrogen and oxygen attached to them. Complexity of carbohydrates is a spectrum, with formaldehyde being at one end and ultra-complex molecules such as huge amino-saccharides or polymers on the other. Saccharides are sugars, who all belong to the carbohydrate family. As far as nutrition is concerned, most sugars are based on the glucose molecule, that's a unit with 6 carbon atoms typically wound into a ring with six or five edges. Chaining those rings together makes polysaccharides.

Overly long saccharide chains only fit into our sweetness taste detectors at one point, that's one ping each from a huge number of saccharide rings. Smaller sugars (like dextrose) cause a lot more signal by fitting better into the detectors, that's why they tend to taste sweeter. Polysaccharide disassembly starts with enzymes in the saliva of the mouth, that's why some things get sweeter when you chew on them for a while. For people who don't gobble down their food to quickly, that means only small sugar molecules even arrive in the small intestine, where they are further split into monosaccharides which can finally be resorbed through the intestinal wall. The small intestine is ill-equipped to handle longer chains, though, that's why they pass into the large intestine. In itself that's not a problem, but if there is a _regular and large_ amount of this stuff in the large intestine, it will attract microbes that live off it.

So if a lot of sugars regularly make it into the large intestine, chances are there will be a population of bacteria (or worse: funghi) taking advantage of that. It's not like the bacteria cause obesity as some articles suggest, their presence is itself a symptom of a nutritional problem (such as too much intake). Of course sometimes these colonies cause other problems like inflammatory reactions that eventually necessitate flushing them out. But saying those bacteria cause obesity is just the new "I'm not fat, I'm big boned", a mechanism designed to deflect the responsibility for obesity away from a person's behavior.

The digestive system is designed to survive and thrive on a variety of food, but there is also a lot that can go wrong. It's not "evil complex polysaccharides" wreaking havoc and producing energy out of thin air to make people fat, it's (as always) people eating too much who are bringing this upon themselves.

One good thing food cults such as the different "nutrition plans" and "strategies" can do, however, is making people reflect on their habits and generally lower their energy consumption. To make it extra clear: I don't think vegetarianism is one of these cults, but it too causes people to eat more carefully.


Thanks for the very informative comment. I also recognize that a lot of people's understanding of food is scarcely more rigorous than cargo cult rituals, but a few points seem a bit unclear to me.

...It's not like the bacteria cause obesity as some articles suggest, their presence is itself a symptom of a nutritional problem (such as too much intake)....

How do you square this with the claim from the original article that giving mice a toxin produced by gut bacteria (Lipopolysaccharide endotoxin) causes obesity and insulin resistance, and that "[m]ono-association of germfree C57BL/6J mice with strain Enterobacter cloacae B29 isolated from the volunteer’s gut induced fully developed obesity and insulin resistance on a high-fat diet but not on normal chow diet, whereas the germfree control mice on a high-fat diet did not exhibit the same disease phenotypes"?

It's not "evil complex polysaccharides" wreaking havoc and producing energy out of thin air to make people fat, it's (as always) people eating too much who are bringing this upon themselves.

Why, then, do some people become obese when they eat as their instincts tell them, and others do not? For example, I eat whenever I'm hungry, stop when I'm full (or even overfilled), snack frequently while working (mostly nuts, dried fruits, and sometimes Fritos), and yet remain thin, while others eat carefully and remain obese. What's the difference?


> How do you square this with the claim from the original article [...]

I think the article makes some dubious claims, mostly centered around a single human volunteer (!), using a mice experiment to back that up - I'll remain skeptical until it can be reproduced by another team. The inclusion of Traditional Chinese Medicine alone as playing a key role to curing the condition is a huge tipoff that something is amiss.

But even taking all those doubts into consideration, let's entertain the hypothesis that this bacterium does produce signals that make a person eat more. It's possible. But you still acquire the bacterium by eating too much in the first place. It simply couldn't colonize you if you didn't.

> Why, then, do some people become obese when they eat as their instincts tell them, and others do not?

My personal opinion is there are two big factors. First, lifestyle. People eat too much because that's simply how they live their lives. It may be because they only have access to high-calorie food, or because everybody around them eats too much, or because they have made a habit of eating too much. The second group (which I'm a part of) is worse: for them, food is an addiction. Many of them may already eat "healthy", high-quality stuff - so moving away from fast food does nothing for them. Eating simply has the same effect on them as drugs do on other people.


You do not acquire bacterium by eating too much. You acquire them by being exposed to them -- kissing the wrong person, sitting beneath a contaminated window air conditioner blowing on you, etc. Yes, they then need to colonize you to become a big problem. You have zero evidence to support your claim that eating too much is a prerequisite for their ability to colonize you.


I already outlined the mechanism in my first post. Kissing and ACs are not the reason you get these organisms inside you. They are already everywhere. Just by moving through life, you're exposed to a huge variety of enterobacteriae. You wouldn't believe how everything is just covered with E. coli, for example. It's not a matter of staying away from dirty surfaces, or of wiping everything down with disinfectant. These organisms are omnipresent, and it's normal for them to live inside your gut as well. In fact, the majority of them are endosymbionts, and are regulated by their environment. This means whatever comes into your colon determines which bacteria get to thrive on it. This is not my claim, it's basic biology.

I invite you to do the following experiment at home. Get yourself a petri dish and fill it with sterile Agar. Then wash your hands. After that, make some fingerprints in the Agar. Incubate for a few days. You'll be surprised.


Oh, I am very well aware that germs, fungus etc are rampant. But you have to be exposed to a specific one to catch that specific one. There has to be a vector, whether it is a dirty surface or another person or something else. Your view amounts to "vague miasma -- no specific source", which is a view that annoys me. It came from somewhere. It didn't just magically pop into existence from the ether because "you ate too much".

I really don't know how to discuss this with you. You blame everything on "behavior" then claim to have a food addiction. Your view strikes me as rather handwavy, while dismissing a possible specific cause for some individuals: exposure to a pathogen. This is not the first time I have heard this, so I doubt that there is only one study.

No, I likely cannot convince you of anything. But you are equally failing to convince me.


First, let's do away with the hostility. I don't know what I have done to provoke it but it's certainly not worth discussing anything in this manner. It's important not to engage in willful misunderstanding, or conflate separate points I made into some kind of chimera to distort what I said.

> You blame everything on "behavior" then claim to have a food addiction.

This is certainly a gross mischaracterization, and I can only assume you're using it to aggravate me somehow? I invite you to read again what I actually wrote regarding this and several other different issues. I'm not sure if you're just trying to troll me or if you actually want to have a discussion, but I'll just assume you're not trying to behave like an asshole on purpose and move on.

You misunderstood my point about how gut bacteria take hold in the first place. Mostly, enterobacter strains are something which lives inside people's guts anyway. There are several pathogenic strains but this is not what the article is talking about. We're talking about an organism that lives off what you feed it. There is nothing hand-wavy about that. It's just a fact. Just as food intake determines individual weight-gain, the availability of nutrients in combination with its environment determines the amount present of a given gut bacterium. It's also a fact that our daily environment is rich in gut (and other) bacteria.

> It didn't just magically pop into existence from the ether because "you ate too much".

I failed to explain this properly then. People have a certain mixture of different gut bacteria inside them, they also tend to acquire them in the "hand-wavy" manner described above. Now, a bacterium needs to eat in order to survive and reproduce. Different bacteria are optimized to eat different things in different environmental conditions. If E.c. colony size is indeed statistically larger in obese people (a point that still needs to be shown conclusively), the reason for that will be that they get a lot of nutrients under favorable conditions. There is nothing magical about it, just basic biology.

> No, I likely cannot convince you of anything. But you are equally failing to convince me.

It depends where you're coming from. I'm not even sure we're speaking the same language, otherwise I can't explain how some of my points could have come across in such a distorted fashion (even taking into account my infamous inability to communicate). In some sentences you portray my views as exactly the opposite of what I actually said. I really mean it when I say I'm sorry we're at this point, but I'm also unsure what I could have done better.

Also, a meta point: have we done this before? I'm not sure.


I don't recall "doing this before" with you in specific. I recall talking to you. I recall it was amicable, which is part of why I replied at all. But this type thing does happen to me a lot on the internet generally, which is incredibly frustrating for me personally. It also happens a lot on HN specifically: I get dismissed by people who are convinced they know science, thus their vague generalizations and personal opinions apparently do not need to be backed up. Granted, it's a huge sore spot for me, but your latest reply doesn't strike me as remedying that at all, though I do appreciate your willingness to discuss it.

There are a lot of people who are either obese and have tried everything and can't lose weight or are thin and have tried everything and can't gain weight. But your opinion is "some people just eat too much", apparently with no real cause. Equally, you are comfortable with "bacteria are everywhere -- if you eat too much you can grow them". You really aren't willing to admit that different people carry different bacteria due to exposure of some sort and this might be a factor in why some people "just eat too much". In your view, the eating too much has to precede the bacterial overgrowth. Seems awfully convenient. But people don't get AIDS or anything else because "well, germs are everywhere". They get AIDS from an infected lover or contaminated needles or due to exposure to some other specific vector. You can "eat too much" all day long and if you weren't exposed to a specific pathogen, you won't grow it.

I have lost enormous amounts of weight in recent years. I never counted calories. I had zero goal of losing weight. My only goal was to kill off the overgrowth of germs which were killing me. Last year, I lost so much weight, so rapidly that total strangers began stopping me in public places and asking me how I did it. I did not feel like getting into my medical situation, so I made vague noises about dietary changes and walking a lot. However, I am a sample of one, so that will also be dismissed by most members of this forum as "not scientific".

I really doubt this discussion will do much for either of us. I regret making my initial post. I really should know better by now, but my recollection was that you are a very reasonable member of the forum. So I chanced it.

Please have a good evening.


"Last year, I lost so much weight, so rapidly that total strangers began stopping me in public places and asking me how I did it."

How did strangers know that you'd lost weight?


I have lived without a car for several years, so I walked everywhere. Sometimes people would stop me in the grocery store or other place and say "I see you walking all the time. God, you've really lost weight!! What are you doing?" I also worked for an extremely large company. There were probably about 2000 people in the building where I worked. So people I did not know at all would stop me in the hallways at work and ask how on earth I was dropping so much weight, so fast.

I am tall with naturally curly hair and apparently striking features. It isn't terribly uncommon for people to notice me whom I never noticed. That sort of experience goes back at least to high school, where people recognize me and I have no clue who they are. (Edit: This is probably compounded by my crappy eyesight. I sometimes don't recognize people whom I do know until I am practically on top of them.)


I didn't intend to dismiss you, that's why this whole thing struck me as odd. I said some things that I didn't recognize anymore when you repeated them, however re-reading my original post confirms they are still there. They just didn't come across somehow, and I'm entirely ready to accept responsibility for that (maybe it's because English is not my first language). It's just a topic where I didn't expect any bitter misunderstandings, that's why I'm so surprised. For what it's worth, I also made it abundantly clear in my posts above where the line between my opinion and scientific fact is - all the more frustrating you chose to attack me as if that line wasn't there. For what it's worth, I do know bioscience, but I also realize that arguments from authority don't mean much, that's why I don't like to preface posts with "I'm a [insert area of expertise here]". I never said anything amounting to "I'm an expert, trust me", instead I believe this is basic stuff that anybody can understand if they make an effort.

Having discussions with smart people who disagree with me is one of the reasons I enjoy HN so much. But it is no fun if key points are misunderstood, ignored, or repeated out of context. So I really wanted to find out why this was happening.

I won't repeat things I said earlier, but as a summary: I really don't think there can be any contention about the growth mechanism of bacteria. As a point of personal opinion, I have voiced doubts about the study and its methodology. I also expressed a personal theory on two major factors that make people fat, one of which I (somewhat regretfully) tied myself to.

> There are a lot of people who are either obese and have tried everything and can't lose weight or are thin and have tried everything and can't gain weight.

Those two are very different. There is absolutely no doubt that obesity comes from excess intake of energy. None. Some diseases cause the body to grow excess tissue or to store water excessively, but that's not obesity. Failing to gain weight, however, can be down to a lot of factors both behavioral and biochemical.

> But your opinion is "some people just eat too much", apparently with no real cause.

I did not say that or anything even resembling that.

> Equally, you are comfortable with "bacteria are everywhere -- if you eat too much you can grow them".

It's a simplified summary, but it's fair.

> In your view, the eating too much has to precede the bacterial overgrowth. Seems awfully convenient.

I don't think that's convenient for anybody. It's just the only way you can multiply microorganisms to any significant numbers.

> But people don't get AIDS or anything else because "well, germs are everywhere".

That one leaves me a little speechless. HIV is a virus, it doesn't have a metabolism of its own. It's a rogue piece of software that hijacks the human runtime, so to speak. That's an exceedingly bad example, but there are bacteria out there that would be much better suited for the point you are trying to make: Take MRSA for example, because it grows and lives off living human tissue. Contrast that to the enterobacteria we were talking about originally, they live off our waste products. So it's clear why, for example, E. cloacae is directly related to the food you eat, but MRSA is not. MRSA attacks the body and provokes an immune response, E.c. does not. That's also the reason why MRSA is something you contract, whereas E.c. is something which in all likelihood you already have. It's worth repeating that enterobacteria actually lend essential assistance to our digestive system.

> My only goal was to kill off the overgrowth of germs which were killing me.

Now I understand so much better where you're coming from. We could have saved a lot of time... Whatever works for you is fine, I didn't want to sabotage that - nor did I have any idea why my dry descriptions provoked such a visceral response, but now I see why.

> I really should know better by now, by my recollection was that you are a very reasonable member of the forum.

Well, I do think this exchange was worth pursuing in retrospect. I do try to be reasonable, though of course I often fail. I'll just have to try harder :)


I think there can be contention about the growth mechanism. Again, my main "proof" is I got better after being sentenced to death. Trying to talk about that gets me dismissed in the ugliest way possible. On HN, I was recently repeatedly accused of being mentally ill and hounded by someone claiming I was being irrational and overly emotional. I remain baffled that no one seemed to recognize his behavior as irrational and overly emotional. My only crime is telling a truth which people find so fantastical that they feel entitled to claim I made it up. I am at wits end as to how to carry on a rational discussion in the face of that. I am trying to figure out what I need to do to present my case more effectively. But I also frequently wish that I could, conveniently, just shut up about it and let other people keep dying, like they seem to prefer. I don't know how to do that. It is an option I often contemplate. But I seem to be equally unable to do that. One of those "sucks to be me" things.

I really don't wish to discuss this further in this thread. Again: Please have a good evening.


Again: none of those things are actually happening in this thread. I'm not disrespecting you, I'm not accusing you of anything, but I also don't think I'm being irrational. I do believe you didn't really read my entire posts though, but that is more a failure on my part than on yours.

Also, it's actually morning here in Europe. In the spirit of a new day: don't ever shut up, but do lighten up.


Cheers guys, loved reading your debate. Thank you both for contributing!


I think one case where someone might object to your comments is the assertion that obesity is strictly a behavioral problem, in the form of overeating. While that may be strictly true by virtue of the conservation of matter and energy, the word "behavioral" can be interpreted as meaning "chosen," as in, "People are obese because they want to be obese." It may be helpful to note that there are many causes for behavior, including conscious effort, habit, addiction, autonomous instinct, reflex, and perhaps even lipopolysaccharide endotoxin.


Absolutely, I didn't mean to imply that behavior is the same as choice. It didn't occur to me that could even be an issue. It's a neutral term.


To people fighting a personal fight in the middle of the battlefield, neutral terms can become not so neutral very quickly :-).


> Why, then, do some people become obese when they eat as their instincts tell them, and others do not? For example, I eat whenever I'm hungry, stop when I'm full (or even overfilled), snack frequently while working (mostly nuts, dried fruits, and sometimes Fritos), and yet remain thin, while others eat carefully and remain obese. What's the difference?

I really really want to see good quality food diaries for people who claim to eat little but not lose weight. I'd also want to see how much exercise they do. (And not even actual exercise, just how much they move around during the day.)


> It's not like the bacteria cause obesity as some articles suggest, their presence is itself a symptom of a nutritional problem (such as too much intake)

this article suggests the bacteria are causing obesity, and explores it by having a flora transplant into a regularly non-obese mouse that causes obesity in that mouse.


Tangential, but: is the whole obsession with fiber a bit misguided? If polysaccharides are largely responsible for feeding gut bacteria (good and bad), and your link recommends cutting them out, then by definition, we should be cutting out dietary fibers (most of which are polysaccharides). Fiber is mostly undigestible in our stomachs and upper GI tracts, but is readily fermented by (and feeds) intestinal bacteria.

Or am I missing something here? Someone with a bit more knowledge of organic chemistry and biology can feel free to chime in here.


The fiber helps your bowels work correctly. We were not created to evacuate bricks. You don't need a PhD in organic chemistry and biology to understand that, just experience with babies.


Well, yes and no. A lot of cultures live almost exclusively on carnivorous diets, in which vegetable fiber is extremely rare (if eaten at all). Evidently the fats in the diet serve as lubricants in the absence of the mechanical action that fibers serve in the intestines.

I'm not disputing that fibers help "push things along" by absorbing water, adding bulk, etc. But are we overeating them? Do we really need to be making a conscious effort to add or supplement them in our diets?

FWIW: I'm not pushing some sort of anti-fiber claim or agenda here. I'm neutral on the subject. I'm simply inquiring.


> A lot of cultures live almost exclusively on carnivorous diets, in which vegetable fiber is extremely rare (if eaten at all).

Eskimos' diet is not a parameter to anyone other than Eskimos. Those populations have adapted to survive on those diets, and even then, with drawbacks to health and life expectancy. Also, Eskimos are certainly the exception, saying a lot of cultures live on meat only is a stretch.

> I'm not disputing that fibers help "push things along" by absorbing water, adding bulk, etc. But are we overeating them? Do we really need to be making a conscious effort to add or supplement them in our diets?

Fibers are integral part of a diet with minimal amounts of fruits, vegetables or grains. You don't need to add fibers unless all you eat is processed food.


I think that depends in part on who your ancestors are -- I.e. do you have genes from a carnivorous culture?

My exhusband is part Viking, basically. They ate a lot of meat, in part because they lived so far north that you couldn't grow enough plantbased foods. My ex ate a very high meat diet. Our sons eat less meat than he did, but they are 1/4 Norwegian whereas he is 1/2. Still, they tolerate more meat in their diet than I do. I am convinced there is a genetic component here.

(Yes I know: Anecdotal and all that.)


The vikings actually were mostly crop farmers. Due to the weird way Caribbean waters flow up through the Atlantic and past Brittian.

http://www.danishnet.com/info.php/vikings/farming-152.html


Sorry, I didn't mean to suggest that Vikings only ate meat. Just that they appear to have eaten a lot more meat than most other Europeans (I am mostly German and Irish in ancestory). That isn't inconsistent with my point that genes likely influence one's tolerance in this regard.

Even the site you link to talks about lamb and other meat being a regular part of the Viking diet. In Europe, the children's rhyme "peas porridge hot, peas porridge cold" refers to the common practice of serving some sort of hot meal at lunch and cold leftovers at dinner. Peas porridge was likely either vegetarian or had very little meat in it. When I had some poetry class in college, it pointed out that "Greasy Jane stirs the pot" suggested a servant in an upper class household preparing a dish containing meat, which was something of a luxury item. The "greasy" imagery indicates it contained meat. Peasants could not afford meat on a routine basis. Further back in history, Romans ate far more eggs than meat.

My ex was a history buff. We talked a fair amount about things like that.

Sorry for the sloppy wording earlier.


"We were not created to evacuate bricks."

"Created?" This is definitely the wrong concept to refer to here. The correct sentence is (correct because it takes mountains of scientific evidence into account):

"We were not evolved to evacuate bricks."


Non-digestible fiber helps your bowels move. Digestible fiber actually slows bowel action.


Most people are not aware that "fiber" is really just chains of sugar. I suspect this is where a lot of conflicting advice comes from.


Interesting how the book in your link disallows all whole grains, while the linked article specifically point out that the patient's diet consisted of "whole grains, traditional Chinese medicinal foods and prebiotics".

They also disallow milk, but allow cheese. My ancestors didn't spend thousands of years evolving lactose-tolerance for nothing, you know.


"[the pathogen] can induce obesity and insulin resistance via an inflammation-mediated pathway"

This is why weed reduces one's risk of diabetes and also often helps obese people lose weight.[1] For what it's worth, you can now actually (supposedly) buy CBD (supposedly) legally online:

http://dixiex.com/

CBD is one of the more common non-psychoactive cannabinoids in marijuana, and it is responsible for many of the anti-inflammatory benefits. While more research is needed, lots of people are reporting the same sorts of benefits that this research is reporting, but without the obvious negative side effects of taking anti-biotics. (Whether there are negative effects of longterm CBD use is anyone's guess, but as far as I know nothing has been discovered so far.)

[1] http://blog.norml.org/2012/12/12/study-cannabis-associated-w...


CBD is most definitely psychoactive. It also accounts for about 25-50% of marijuana's active components, so we are living in a world full of long-term data.

Cannabidiol is most definitely illegal in the US, too. That DixieX site you link to is just hemp oil products -- no psychoactives.


CBD is considered non-psychoactive by fiat. This is because it has a low affinity for receptor sites in the brain and it doesn't cause significant impairment. You may or may not be able to feel it though. And it's definitely not 25-50% of most commercial strains (unless specifically bred for it), that may be true of certain landrace varietals though.

Also the amount of cannabinoids DixieX is citing is actually the minimum CBD content. They show their lab results on their Facebook page. The reason the don't cite the CBD content is because CBD is illegal, but hemp products are legal if the THC content is below a certain level. They're trying to play it off as a legal grey area and are taking a calculated risk.


It's surprising to me that CBD is fiat-legal; not only is it a prominent cannabinoid, it's one acid wash away from becoming THC. http://www.bluelight.ru/vb/archive/index.php/t-351514.html

And I don't mean 25-50% of the plant mass, I mean CBD will often make up 25-50% of an extract. (Wikipedia has my back with a 40% figure: http://en.wikipedia.org/wiki/Cannabidiol)


"It's surprising to me that CBD is fiat-legal"

Fiat non-psychoactive, not fiat legal. It's definitely still illegal. But it's included on all the lists of non-psychoactive cannabinoids.

As for that journal article, it's behind a paywall even though it's from 1940 so I can't comment on it. But if you look at the menus for any dispensary that tests for both THC and CBD, you'll see that CBD is rarely a significant percentage of the cannabinoids, e.g.

http://www.greendoorsf.com/menu/high_end.php


Great points. The sooner this medicine can be freely accessible and available to all the better.


I thought the problem with refined/processed foods was that they were too easy for our bodies to absorb. Or is that true, but the amount consumed still results in a lot of 'leftovers'?


Yeah that seems a little counterintuitive at first, but your assumption is correct. You still absorb lots of cheap calories from the sugars / carbs that you eat, but there's still plenty of leftovers for the bacteria. Everyone's different though - some people may have no issues at all, others are extremely sensitive.


No. It is pretty much impossible to overload your body's ability to absorb carbohydrates without a) exploding your stomach or b) you have some other health problem. By the time the food you eat gets to the bacteria, there are no sugar, fat or protein left. We absorb it all. We store extra of the first two and excrete the third (in a modified form) through urine.

Refined/processed food should be eaten in minimal quantities because it spikes blood sugar and causes insulin fatigue, which in the long run causes Type II diabetes.

And I'm in medical school, so yes, I do know what I'm talking about.


>By the time the food you eat gets to the bacteria, there are no sugar, fat or protein left

You realize those bacteria are living off the fat, sugar and protein you consume right? They are essential to our ability to utilize the chemicals we get from these macro nutrients.

>Refined/processed food should be eaten in minimal quantities because it spikes blood sugar and causes insulin fatigue, which in the long run causes Type II diabetes. True, but this also an increasingly old school and one dimensional way of thinking about how type II develops. There are a host of genetic and environmental factors that effect an individual's response and eventual tolerance to insulin.

Sadly, being in med school does not guarantee you "know what you're talking about", in fact, even after you get to wear that white coat you'll probably realize you know way less than you could ever imagine. The perception that kind of attitude creates only narrows our minds and hurts our patients.

I'm done with med school.. and I realize on a daily basis I still have no clue what I'm talking about :)


Stop calling them "our patients" and saying you are done with medical school. You submitted a post 227 days ago saying you worked in your dad's doctors office doing various IT tasks. Don't claim authority of passing four+ years of incredibly difficult schooling followed by several more years of intense residency. You don't deserve it so don't claim it.


Yeah your own submission says you're a clinical coordinator and in charge of "it stuff." You didn't go to medical school.


> Refined/processed food should be eaten in minimal quantities because it spikes blood sugar and causes insulin fatigue, which in the long run causes Type II diabetes.

What precisely does refined/processed food mean, from a chemistry standpoint? Is there a particular common process that transforms my homegrown lettuce into "refined lettuce"?


The refining process breaks down complex carbs into simpler carbs.


I've also heard that eating smaller meals, more regularly, can help your body lose weight.

This trend correlates well with the above idea, since smaller meals means that the sugars should be absorbed before the large intestine, thereby further robbing the bacteria of their food.

It would also explain the opposite effect - that eating larger meals makes losing weight harder, since the larger quantity of food has a better chance to get to your large intestine.


You can pre-order a kit to get your intestinal biome mapped for $69. See http://www.ubiome.com/


This is one of the first times I've heard such a confident voice of reason regarding this topic in such a liberal atmosphere. Thank you.


I went straight to the food list. They lost me at coffee should be VERY weak. They can't take that away from me! :)


I'd love to see this study enrolled in the Reproducibility Initiative: http://reproducibilityinitiative.com

Strong claims require strong evidence.


ISME Journal.

1. Two independent facts from the experiment: A pathogen that causes obesity (in mice) seems to be active in some obese humans.

2. Severely restricted diet seems to powerfully reduce the population of this organism.

I doubt that these facts are unrelated. It's classic host-parasite behavior. The pathogen depends on high calorie intake in its host, and therefore engineers that behavior (somehow).

Further there is no reason to make the leap that the only or best way to counter this pathogen is through diet. It's not impossible that a targeted antibiotic that eliminates this pathogen would have an effect on the body composition of the host.


Very interesting observation re parasitic behavior. I suspect that with modern food processing techniques to make food relentlessly cheaper, we have unwittingly enhanced the food supply for the parasite.


It's not really unwitting. Anything that increases nutrition for humans necessarily increases the food supply for creatures that prey on humans. Similarly, boosting the rabbit population enhances the food supply for creatures that prey on rabbits.


They could probably make a targeted antibiotic, but gut bacteria are something not very well understood yet, and it's a highly complex ecosystem (some would say more complex than our own cells) that differs significantly from person to person.

they have done studies though to see if doing a guy bacteria transplant from a healthy person to an obese person would change their weight, I believe there wasn't any difference found for weight loss but that there was some hope in using it as a treatment for diabetes. I'd have to look it up.

This particular study though I wonder if it was the calorie restriction, the weight loss or the content of the diet that caused the changes to happen.


Ok, this is an interesting observation:

"After 9 weeks on the WTP diet, this Enterobacter population in the volunteer's gut reduced to 1.8%, and became undetectable by the end of the 23-week trial"

So the thesis is that this bacteria lives in obese people's gut, and it makes them more obese. But once they diet to a point where they are not obese, the bacteria dies off? I wonder if they are going to try a diet + anti-biotic treatment, diet + placebo trial on two obese patients to see if it improves their chances to get back into a regular balance.


For people who didn't read the summary - that patient who lost 30kg and reduced their bacteria population was on anti-biotics. So, right, it would be interesting to see if that bacteria reduces without the anti-biotics.

But before you think the researchers left a big hole in their research, remember that the addition of bacteria makes mice obese. Now if we could just try that on humans...

edit: As pdx points out below, not antibiotics, pre-biotics. Big difference.


The patient was not on antibiotics, he was on prebiotics. So, this is something you could do yourself without a doctors cooperation.


The WTP diet is described as 'whole grains, traditional Chinese medicine and prebiotics'. Perhaps there's an active ingredient in the traditional medicine (e.g. an antibiotic occurring in plants)?


Also, a lot of spices have antibiotic properties, and some oils. Food and its impact on health is more chemically complex than most people seem to realize.


No antibiotics were involved but the WTP diet consisted of 1344Cal daily diet of canned porridge (. . ."4 cans of gruel per day" . . .) - Quoted from 'Supplimental Material' to the original study publication http://www.nature.com/ismej/journal/vaop/ncurrent/extref/ism.... But, there is absolutely no specific information as to the actual ingredients of the "porridge/gruel" so there seems to be no way to actually repeat this research or try the diet individually.


So they basically put him on a strict low calorie diet, and he lost weight? No way!


Please stop oversimplifying. With the existence of the bacteria, mice were obese. By means of their diet and prebiotics, they were able to reduce the levels of this bacteria in their subject.

Could be just the caloric deficit, could be the bacteria. It's an interesting correlation and should be explored further.


I have just finished reading the entire report including the supplement. It seems that the reason this bacteria was killed off is that the diet changed the pH balance in the gut. The report mentions "Bitter Melon" as killing the bacteria (Supplementary Figure 1. Bitter melon markedly modulated the human gut microbiota in in vitro experiment) Supplementary document, page 33. I couldn't find an exact reason for the subject taking the pre-biotics but I would suspect that it is to help re-colonize the gut with 'good' bacteria.


But once they diet to a point where they are not obese, the bacteria dies off?

I believe the theory is the reverse - by killing off the bacteria, the person becomes less obese.

Anti-biotics probably won't work as well as you hope because they kill all the bacteria in the gut - good and bad - which will just create more digestive problems.


Poop transplants. Sounds gross, but can apparently work.


It paints this animation of the spread of American obesity in a new light: http://en.wikipedia.org/wiki/File:BRFSS_obesity_1985-2006.gi...


Epidemic?


It is interesting to consider that periodic fasts and/or abstaining from certain foods for a time (such as Lent during the Orthodox calendar), seen in many religions, might have a health benefit by suppressing certain gut bacteria, or at least managing gut flora.


Is it actually interesting? Even the rules were chosen randomly, you'd expect any large body of rules to get something by sheer chance alone.


yes, it is interesting. Consider that vitamin C was known to prevent scurvy, but then that knowledge was lost, and rediscovered later on. How much knowledge may be codified in ancient customs, and that we might have forgotten the foundations for that knowledge.


Vitamin C was not known to prevent scurvy. Citrus fruits, which contain vitamin C, were known to prevent scurvy, but no one knew why. They had theories, but the theories were wrong.


It might better be viewed as a behavioral "mutation" of sorts that improved the viability of those who adopted the practice. There are many interesting things that happen by chance.


American obesity is a recent thing that does not eg seem to be related to stopping fasts.


The article is very interesting. I looked, but couldn't find information on the exact diet of the test subject during the study. Did anybody else have any better luck?


The supplementary information link at the bottom has a link to the diet and how it was prepared:

Dietary intervention and sampling. This volunteer was given a diet composed of whole grains, traditional Chinese medicine and prebiotics (WTP diet) for intervention. He was given 4 cans of gruel per day as staple food contract prepared in the form of cooked porridge (370 g wet weight per can) then canned by a food manufacturer (Shanghai Meilin Meida Food Co., Ltd.) for 23 weeks. Each can contained 100 g dry ingredients (59 g of carbohydrate, 15 g of protein, 5 g of fat, and 6 g of fiber) providing 336 kcal energy (70 % of carbohydrate, 17 % of protein, 13 % of fat). Fresh fecal samples were collected with 4 or 5 weeks intervals. Whole blood and serum samples were collected with 0, 9 and 23 week (0d, 9w, 23w). All samples were immediately frozen on collection and stored at -80 °C for subsequent analysis.


Is it just me or isn't that basically what they feed you in the Matrix?

"Tank: Here you go, buddy; 'Breakfast of Champions.' Mouse: If you close your eyes, it almost feels like you're eating runny eggs. Apoc: Yeah, or a bowl of snot. Mouse: Do you know what it really reminds me of? Tasty Wheat. Did you ever eat Tasty Wheat? Switch: No, but technically, neither did you. Mouse: That's exactly my point. Exactly. Because you have to wonder: how do the machines know what Tasty Wheat tasted like? Maybe they got it wrong. Maybe what I think Tasty Wheat tasted like actually tasted like oatmeal, or tuna fish. That makes you wonder about a lot of things. You take chicken, for example: maybe they couldn't figure out what to make chicken taste like, which is why chicken tastes like everything. Apoc: Shut up, Mouse."

http://www.imdb.com/title/tt0133093/quotes?qt0324288


Excellent quote and that sums it up nicely for me. Gack from a can. Yumbo.


So, only 1344 cals per day.


One can argue it was the calorie restriction and not the bacteria. However, the interesting part was that the pathogen then caused the mice to gain weight.


I found it mystifying they did much to talk about the man's weight loss diet at all, as that wasn't the science part, the mice feeding was.

But hey, perhaps they can get a study going on it to determine the causal relationship between the endotoxin, human obesity, and intestinal flora.


Probably because it made the subjects want to eat more. There's no magic bullet for gaining or losing weight, you either eat more or less that your body needs.


It's funny, how you first said there's no magic bullet, then provided everyone with a magic bullet.


Controlling calorie intake is hardly a magic bullet. That's like saying exercise is the magic bullet for gaining muscle or studying is a magic bullet for passing exams.

A magic bullet in this case would be something that allowed weight reduction with no restriction of calories. From experience, restricting calories long-term is very difficult.


Dieting isn't a magic bullet you fool, it's long, hard and worth it.


Just being hard, or even applicable in some cases, doesn't make it less of a magic bullet when someone suggests it's applicable to a broad problem.


Interesting. Being satiated after a meal is really a marker for obesity - if you eat less to get to your satiation point vs. someone else who has to eat more to get there, you're less likely to put on the pounds. I wonder if this pathogen messes with that sense of being satiated.


Someone made a comment yesterday on another site about how we are still living in the bacterial age.

It's a strange notion, that bacteria still own the earth, but we are host to more bacteria than we are our own cells. It's such an interesting yet scary thing to think about - does higher order life exist solely as vessels for bacteria propagation?


Well bacteria are a lot smaller than our own cells, so comparing them by count doesn't seem very meaningful.


By mass, bacteria is still the dominant lifeform on earth.


Yeah, that's cool. Any idea how much mass of a human they make up?


Less than 2kg.


Mind-bending, eh?

It's not too scary a though though -- taking the evolutionists point of view, there is no "underlying" reason that higher order life exists. It exists because the processes of natural selection have enabled it to exist and reproduce.

If bacteria contribute to the survival and reproduction of our species (they do), then they are simply part of the process. It goes both ways. We exist and reproduce because they help us do so, and they exist because we provide a nice host. One hand washes the other...


How's that saying go? 'Life - the whim of a few billion cells to be you for a while'.


This an interesting article by the Economist about the human microbiome ("Looking at human beings as ecosystems"):

Link: http://www.economist.com/node/21560523


Two interesting notes from the abstract:

"The endotoxin-producing Enterobacter decreased in relative abundance from 35% of the volunteer’s gut bacteria to non-detectable, during which time the volunteer lost 51.4 kg of 174.8 kg initial weight and recovered from hyperglycemia and hypertension after 23 weeks on a diet of whole grains, traditional Chinese medicinal foods and prebiotics."

"The obesity-inducing capacity of this human-derived endotoxin producer in gnotobiotic mice suggests that it may causatively contribute to the development of obesity in its human host."


This is potentially huge news. If it can be replicated you can take all the high-fat/low-fat, high-carb/low-carb, paleo whatever diets and chuck them. "we show that one endotoxin-producing bacterium isolated from a morbidly obese human’s gut induced obesity and insulin resistance in germfree mice." "Germ-free mice" are mice raised from before birth with no germs, so the effect of a single infection can be observed without complications. They claim that a single bacterium strain from a human gut, infected into mice, gave them not just obesity but insulin resistance and inflammatory symptoms -- a close analog of the complex we call "metabolic syndrome" in obese people.

If even some cases of metabolic syndrome can be linked to a simple bacterium -- and cured simply by killing that bug -- this will have the economic and medicinal effects of, well, not the eradication of smallpox, but pretty close.

Scientifically it's the equal of marshal and warren finding the bacterial cause of peptic ulcers -- and they got the Nobel for medicine for that.


>well, not the eradication of smallpox, but pretty close.

Heart disease kills far more people than smallpox ever did. You have a 20% higher chance of heart disease if overweight.


I can comprehend a good deal of code but this medical jargon is making my head spin. Anyone care to summarize this for us feeble minded laypersons? Because it sounds like they found something in obese people that if eliminated could lead to weight loss. I know there are people that can benefit from that when extreme obesity makes regular, "simple" dieting very challenging and exercise impossible.


tl;dr: fat guy lost a ton of weight by a diet that reduced a specific kind of gut bacteria; this bacteria inserted into mice engineered to be thin caused the mice to gain weight.

Ergo, bacteria may be driving obesity.


Not only obesity, but insulin resistance: basically gave the mice the start of "metabolic syndrome", as also observed in obese humans.


So in theory, if a pill was developed to just kill that bacteria, fat guy loses weight.


Maybe big pharma and the food industry knew this the whole time.


Great, another article for fat acceptance idiots to read the title of and declare it cake day.

> The volunteer lost 30.1 kg after 9 weeks, and 51.4 kg after 23 weeks, on a diet composed of whole grains, traditional Chinese medicinal foods and prebiotics (WTP diet, Supplementary Information; Supplementary Figure 1), with continued amelioration of hyperinsulinemia, hyperglycemia and hypertension until most metabolic parameters improved to normal ranges (Table 1). After 9 weeks on the WTP diet, this Enterobacter population in the volunteer's gut reduced to 1.8%, and became undetectable by the end of the 23-week trial, as shown in the clone library analysis (Table 1; Supplementary Figures 2 and 3).


You're right, we should all lament the possible passing of another way of judging people inferior to us.


He missed the part where Monsanto makes a weaponized form of the bacteria that you use against your enemies to make them fat.


I think the Soviets must have beaten us to it.


I don't care if someone is fat. What I care about is the loons saying that it's healthy and fine to be morbidly obese and they use stuff like this to back it up.

"Gut bacteria are the cause, I can do nothing"

"It's genetics"

No, it's calories in vs calories out. Maybe these bacteria make you want to eat more, maybe they somehow pull more energy out of food than normal gut flora somehow, in the end it doesn't really matter. Eat less, lose weight; eat more, gain weight; the definition of 'more' and 'less' are individual.


No, you are still wrong. I am morbidly obese and struggle with my weight daily. It will kill me in the end but I want to know what you would do when your metabolism is so low that your normal body temperature hangs at around 97.2F and resists being raised even by means of medications and heavy exercise. I'm sorry but when numerous doctors over 20 years all throw their hands up and say they can't help then there is nothing to be done. I admit, I could starve myself on something around 700 calories a day for the rest of my life but I would rather die; I think most would. I could hit the gym for 6 hours a day, likely with very little improvement, but I need to work to support myself and my family.

Finally, I get tired of arm chair nutritionists going off and telling people that it is all about eat less and exercise more. Obesity isn't a one solution fits all problem and it is only arrogance to think otherwise.

This article points out that there is yet another possibility to look into. Yet again, something that works against the old mantra eat less exercise more. We simply still don't know enough about the human body. There are going to be many more surprises for the obese population. In the mean time we have to combat our weight and jerks who think they know everything.


If you sport 6 hours a day and do not eat more you are going to lose weight extremely rapidly since you will need at least 4000 kcal just for that sport (compare with a normal daily expenditure of 2500 kcal). If your body really does use significantly fewer calories for the same activity as a normal person I would be very surprised. Millions of years of evolution have already optimized our energy efficiency to the limit. You probably wouldn't survive on 700 calories per day even if you stayed in bed all day, let alone living a normal lifestyle. In fact, just maintaining body fat requires calories, so if activities are otherwise the same an obese person burns through more calories.

That isn't to say that there are no genetic differences that influence body weight, there certainly are! It's just that the mechanism isn't energy efficiency, it's genetic factors that influence how much a person eats and how active a person is.


I am curious if you have experimented with the following:

1. increase iodine intake in some fashion

2. cut out all wheat products including whole grain

3. Atkins-style diet with restricted carbs in general

4. increased use of ginger as a spice or in tea (some believe it helps increase metabolic rate).

5. high intensity interval training (you mention exercise).


Caffine, Ephedrine (it's in congestion medicine like Brokaid in the US) and Yohmbine all have complementary effects on your metabolic rate and the last two have been shown to help speed fat loss while minimizing muscle loss.


I lost quite a lot of weight by focusing on killing germs and altering my biochemistry. I would be happy to talk to you about it in hopes it might help you. If you wish to talk, my gmail account starts with talithamichele.


Thank you for sharing this. Hang in there. Don't let the haters get you down.


If your condition is as you describe than I'm sorry for you but you're one of like 0.1% of the population (probably less). It's fine, you got dealt a shit hand but you aren't saying that being obese is a healthy lifestyle and the thing is other people are.

Everyone I've ever known or read about has gained weight by eating more and lost weight by eating less, again less and more vary from individual to individual but the fact that calories in = calories out for maintenance is a law of physics.


Dude, you're just embarrassing yourself. Stop.

Until you brought it up, nobody had said that this article means fat is a-okay. In fact, the article treats obesity as a disease, so it's the reverse.

If you ever find yourself getting mad at people for what they might say, you are definitely dealing with your own issues.

Doubly so if you take the time to rebut these imaginary enemies in a public forum.


> but you aren't saying that being obese is a healthy lifestyle and the thing is other people are.

But this article doesn't appear to be saying that. So your attack in this thread is uncalled for. Generally, people trying to find a solution to obesity (like these people seem to be) are not in the obesity is a healthy lifestyle camp. They appear to be in the obesity is a problem we should look into camp.


"Calories in / calories out" is far from scientific. 500 calories of ice cream will not have the same effect on your body as 500 calories of lean chicken breast. It's a very rough approximation intended to get people thinking about their calorie intake and expenditures, but it's becoming very annoying to see people representing it as some kind of quantifiable scientific formula.


> I don't care if someone is fat. What I care about is the loons saying that it's healthy and fine to be morbidly obese and they use stuff like this to back it up.

Being morbidly obese and healthy? Very unlikely to be true. Morbidly obese and ok with? That's 100% legit, it's your body and you are free to do as you please.

> No, it's calories in vs calories out. Maybe these bacteria make you want to eat more, maybe they somehow pull more energy out of food than normal gut flora somehow, in the end it doesn't really matter. Eat less, lose weight; eat more, gain weight; the definition of 'more' and 'less' are individual.

Except we already have strong evidence to suggest that calorie deficit diets do not have a causal relationship with weight loss and that those diets are hard to maintain over a long period of time, leading people to have yo-yo issues with their weight.

> I don't care if someone is fat.

When you call fat acceptance folks loons, I don't think you can say that with a straight face.


Except we already have strong evidence to suggest that calorie deficit diets do not have a causal relationship with weight loss

I don't know if you meant something else here, but of course eating less causes weight loss.


There are people who don't believe that. Every time I hear about it I tell them to get to a physics lab because they are a walking Nobel Prize.


Obviously eating less will cause weight loss. The problem is actually being able to eat less and to keep doing that for life. Maybe that is not a problem for you ... so far, but it is a real problem for many people.

This article could shed more light on the obesity problem and solutions to it. For example, it could very well be that our intestinal flora influences our own decision making. There is at least one known case of a micro-organism that does: the toxoplasma gondii.

It is also apparent that people become addict to sugar and that definitely would influence decision making.

On top of that, our behavior is in great extent influenced, if not determined, by the chemistry of our bodies. It may very well be that chemical imbalances caused by a combination of diet, intestinal flora and hormones, causes obesity.

In short, saying that it is simply a problem of calories in and calories out is a gross over-simplification of the problem. Science is way beyond that point.


Not to mention non-fad weight loss programs like Weight Watchers, and all the starving scrawny people in the world as evidence.


"it's your body and you are free to do as you please."

When obese people fly they rarely buy two seats. They can pretend that their state of health doesn't affect the people around them, but they are deceiving themselves.


I'm still technically obese, but better than I was. I'm big, but I'm not exceptionally wide. If I was an inch taller, I'd merely be "overweight". If I were 4 inches taller, I'd be pretty close to "normal" weight.

I fit in a standard airline seat without hanging over the armrest into the next seat, so why should I pay for it? So yeah, my state of health isn't particularly good right now, but it actually isn't affecting anyone I fly with.

Blanket generalizations don't do anyone any good.


Allow me to disagree; the capacity to generalize is at the core of much progress in human thought.

Of course there will always be those who insist on missing the forest for a tree or two -- the forest in this case being my attempt to keep in mind a wholly unoriginal thought: we are not isolated, and the state of our bodies and minds redounds not only to ourselves.


God this calories in / calories out shit has got to die.

Stop leaving out the fucking calorie absorption efficiency factor if you don't want to sound like just as much of an idiot as the people you are complaining about.

Gasoline has a shitload of calories in it. You will definitely not get fat drinking it.

There is literally no one in the field who thinks this is true or ever did. There is certainly an argument about how widely the absorption efficiency varies from person to person, but that's not the same thing as the assertion that it is simply 100% all the time for everyone.


I think you're ignoring a wealth of research just because it doesn't fit with your world-view.

There is a fair amount of evidence indicating both genetic and epigenetic contributions to obesity.

http://www.ncbi.nlm.nih.gov/pubmed/12574619

http://www.ncbi.nlm.nih.gov/pubmed?cmd=Search&db=pubmed&...

http://www.ncbi.nlm.nih.gov/pubmed?term=obesity%20epigenetic...

http://www.ncbi.nlm.nih.gov/pubmed?term=obesity%20genetics


This is how the zombie outbreak starts...




Guidelines | FAQ | Support | API | Security | Lists | Bookmarklet | Legal | Apply to YC | Contact

Search: