7 ms·

Bacteria in the Intestines May Help Tip the Bathroom Scale, Studies Show

58 points by tokenadult 14y ago

ChuckMcM 14y ago
The mouse studies, the C.fid studies, fascinating stuff. Would be a hell of a project to do flora studies. Perhaps we could blend it with Gate's new toilet initiative, press this button if you're you willing to enter a survey of gut flora and a chance to win an Amazon Gift card! Now please don't move while the swab extends ...
brianbreslin 14y ago
Could we see a legit probiotic capsule that is sold over the counter that has fat burning capabilities? so we identify the bacteria common in thin people and let fat people spend $$$ to acquire it?
- gojomo 14y ago
  I'd guess that the balance of bacteria depends more on whole-system factors, especially diet and personal chemistry/digestive-tract-structure. Unless a strain is completely missing, adding a few more of one kind might be unlikely alone to change the equilibrium. Now, if you knocked out the old strains with antiobiotics, the repopulation might be more sensitive to the small amounts first reintroduced. These studies of a wasting disease in Africe offer more hints of the interplay of gut microbiome, diet, and antibiotics: http://www.nytimes.com/2013/01/31/health/antibiotics-can-save-lives-of-severely-malnourished-children-studies-find.html http://www.nytimes.com/2013/01/31/health/antibiotics-can-sav...
jcampbell1 14y ago
Mouse studies always turn out to be a tease when it comes to weightloss. I say we skip all the probiotic piddling and go straight for human fecal transplants. Unfortunately, it is hard to get researchers and patients to agree to get an enema of someone else's poo.
- OGinparadise 14y ago
  Unfortunately, it is hard to get researchers and patients to agree to get an enema of someone else's poo. Money does wonders. And since we spend untold billions a year trying to lose weight or to mitigate it's side effects, the money is there. Even if we lost half an ounce a day, it would be roughly 10lbs a year. More than enough for most people.
- gojomo 14y ago
  It's not that hard when patients are suffering and the treatment works. Fecal transplants are already being done for other disorders, and patients are demanding it: http://www.nytimes.com/2013/01/17/health/disgusting-maybe-but-treatment-works-study-finds.html http://www.nytimes.com/2013/01/17/health/disgusting-maybe-bu...
- daniel-levin 14y ago
  http://en.wikipedia.org/wiki/Fecal_bacteriotherapy http://en.wikipedia.org/wiki/Fecal_bacteriotherapy Human fecal transplants already exist
SoftwareMaven 14y ago
I think this is a great example (well, counter-example) of how screwed up nutritional research has been. We spent the last 30 years trying to shoe-horn the low-fat-low-cholesterol-is-everything, when we had no idea how the body works. It is great to see research like this happening. I've followed nutrition for a long time as I've dealt with chronic weight problems, and things have gotten much more interesting (read: less parroting of the "party line" and more new research) in the last 5-8 years. It's unfortunate that so much time was lost, because it takes 10-15 years to go from mice to people. Now if we could only get some experiments with decent controls, so we can actually learn something.
- cromulent 14y ago
  This research has been around for 30 years. There was one case in the 70's where obese adults were given controlled calculated diets in a hospital and one of them gained weight anyway as her gut flora was so good at extracting nutrients. http://www.abc.net.au/science/articles/2011/05/10/3212802.htm http://www.abc.net.au/science/articles/2011/05/10/3212802.ht... Edit: Here's another link I found in one of my old comments from a week or two ago: http://www.ncbi.nlm.nih.gov/pubmed/17183312 http://www.ncbi.nlm.nih.gov/pubmed/17183312
  - draven 14y ago
    Could it be that varied diets could prevent us (our intestinal bacteria) from getting too good at digesting a specific diet then?
  - crusso 14y ago
    Yeah, and Atkins was talking about the insulin response in the 1970's... but he was mostly ignored (if not ridiculed) by the research community. The GP was entirely correct in stating that nutrition research has been "screwed up".
- yummyfajitas 14y ago
  It isn't screwed up. In broad strokes, we understand very well. Calories in - calories out = weight gain. This has been demonstrated in thousands of lab studies. That's about 85%. Now we are just figuring out details and special cases.
david_ar 14y ago
I really don't understand arguments like this - the problem is that some people have digestive systems that are "too" efficient, and so the "solution" is to cripple their ability to properly absorb nutrients. It seems rather wasteful.
- anonymous 14y ago
  Not quite. More like some people have "hoarding" digestive systems that refuse to let excess nutrients be expelled. I do agree that having people waste food is bad, but having unhealthy obese people is even worse.
- geuis 14y ago
  I don't know if you're thin or overweight. I'm fat, always have been. I'll admit to a past of bad eating habits that put me where I am. But the point is that we live with an excess of calories around us. If I have a certain kind of over-efficient gut bacteria helping me out, the survival mechanism in my situation supports the less-efficient variety. Too many calories, whatever their source, has a huge negative effect on my life.
- OGinparadise 14y ago
  It seems rather wasteful. Honestly who cares? It's not like the food saved will go to feed a starving kid in Africa or something. Food is rotting in warehouses already, so it' more of a logistics /distribution thing. That takes time to solve and is a totally separate issue from the medical one..of people dying and suffering from fat /obesity. Different groups can work on separate issues.
  - king_jester 14y ago
    > That takes time to solve and is a totally separate issue from the medical one..of people dying and suffering from fat /obesity. AFAIK, studies about deaths correlated or caused by being fat have been totally debunked and had nothing to do with body weight in the first place. To that end, one does not die from being fat and being fat doesn't mean you are suffering (except for how people and society treats you as a fat person).
sambeau 14y ago
Does this suggest that maybe we should be sharing each other's poo to prevent our gut being dominated by a single bacteria? And does that suggest, maybe, that obesity is in some way partly caused by modern hygiene and hand-washing preventing this from happening 'naturally'? It seems ironic that, after decades of bleach and bacterial hand-wash, I might be 'cured' of my obesity by eating a capsule someone else's fecal matter.
- adaml_623 14y ago
  The one situation where a suppository is the preferred alternative?
- b1daly 14y ago
  More or less, yes:-) http://en.m.wikipedia.org/wiki/Fecal_bacteriotherapy http://en.m.wikipedia.org/wiki/Fecal_bacteriotherapy
- brent_noorda 14y ago
  Here's how to get rich quick: Open a Fecal Transplant Clinic. Let your clients choose from a pamphlet of slim & trim fecal source (I want that one), and for a modest fee they get the shape they want. People WILL pay for this shit (literally).
draven 14y ago
I read something similar recently (though the blog post itself is from 2008): http://phenomena.nationalgeographic.com/2008/10/06/human-gut-bacteria-linked-to-obesity/ http://phenomena.nationalgeographic.com/2008/10/06/human-gut... The whole gut bacteria thing is quite fascinating. It evolves depending on our diet. The intestinal flora of a fetus is boootstrapped with bacteria from his mother. Gut bacterias can get genes from ingested bacterias: http://phenomena.nationalgeographic.com/2010/04/07/gut-bacteria-in-japanese-people-borrowed-sushi-digesting-genes-from-ocean-bacteria/ http://phenomena.nationalgeographic.com/2010/04/07/gut-bacte... And this kind of symbiosis with bacterias is not limited to humans (the rumen of cows is filled with bacterias that break down normally undigestible components of grass such as cellulose.) I bet research on this symbiosis will produce lots of interesting results!
jacques_chester 14y ago
Before people get too excited, remember, correlation isn't causality (aside: I never thought I'd get to be that guy on HN who says that). It's just as possible that different microbial populations follow from obesity. Actually, it seems more likely that this is the case, given that the populations change after band surgery. And, as always, there is no biological mechanism so far discovered that transcends the conservation of energy and matter. Given how hilariously silly any thread on diet becomes on HN (because for some reason saying "net caloric balance is the sole predictor of long term average body mass" drives people nuts), I believe I will sit this out to avoid getting a severe case of XKCD386.
- cromulent 14y ago
  I'll bite. Net caloric balance is an important predictor, but not the sole predictor. That's why it "drives people nuts" - because it is not true. For example: http://www.newscientist.com/article/dn23127-abnormal-gut-bacteria-linked-to-severe-malnutrition.html http://www.newscientist.com/article/dn23127-abnormal-gut-bac...
- Daniel_Newby 14y ago
  > saying "net caloric balance is the sole predictor of long term average body mass" drives people nuts Because it is like saying that fuel combustion causes car crashes. And then smugly congratulating yourself about how you have solved a major public health problem by prescribing a fuel shortage. > It's just as possible that different microbial populations follow from obesity. In which case transplanting the skinny microbes to a stout animal would make no difference. The research in question shows it does.
ry0ohki 14y ago
They say this explains why gastric bypass works, but from what I've seen, people who get gastric bypass can only physically eat a few calories per day in the beginning without terrible consequences. Eventually you can eat more, and I've seen the weight go back, so I'm confused why it would be bacteria.
- pygy_ 14y ago
  They say it probably accounts for 20% of the weight loss. Outline of the experiment: Take a mouse model of human obesity. Divide your sample in three groups: * Gastric bypass * Sham surgery (fake bypass, the surgical equivalent of a placebo) * Sham surgery + caloric restriction. Observe gut flora change in the first group only. "Graft" some of the gut bacteria of the three groups in obese mice who didn't undergo surgery. Observe a moderate weight loss, only in the mice who received a stool sample of the first group. Here's the abstract: Roux-en-Y gastric bypass (RYGB) results in rapid weight loss, reduced adiposity, and improved glucose metabolism. These effects are not simply attributable to decreased caloric intake or absorption, but the mechanisms linking rearrangement of the gastrointestinal tract to these metabolic outcomes are largely unknown. Studies in humans and rats have shown that RYGB restructures the gut microbiota, prompting the hypothesis that some of the effects of RYGB are caused by altered host-microbial interactions. To test this hypothesis, we used a mouse model of RYGB that recapitulates many of the metabolic outcomes in humans. 16S ribosomal RNA gene sequencing of murine fecal samples collected after RYGB surgery, sham surgery, or sham surgery coupled to caloric restriction revealed that alterations to the gut microbiota after RYGB are conserved among humans, rats, and mice, resulting in a rapid and sustained increase in the relative abundance of Gammaproteobacteria (Escherichia) and Verrucomicrobia (Akkermansia). These changes were independent of weight change and caloric restriction, were detectable throughout the length of the gastrointestinal tract, and were most evident in the distal gut, downstream of the surgical manipulation site. Transfer of the gut microbiota from RYGB-treated mice to nonoperated, germ-free mice resulted in weight loss and decreased fat mass in the recipient animals relative to recipients of microbiota induced by sham surgery, potentially due to altered microbial production of short-chain fatty acids. These findings provide the first empirical support for the claim that changes in the gut microbiota contribute to reduced host weight and adiposity after RYGB surgery. http://stm.sciencemag.org/content/5/178/178ra41 http://stm.sciencemag.org/content/5/178/178ra41
shin_lao 14y ago
What happened to eating less?
- segmondy 14y ago
  people want to have their cake and eat it too.
- epo 14y ago
  Sshh, don't be insensitive, some people have a rare metabolic disorder.
  - shin_lao 14y ago
    Sure. That's why one third of the USA is overweight. Probably a rare metabolic disorder. ;)
crusso 14y ago
Freakanomics had a good podcast on the subject of the healthful role of bacteria in the intestines. They covered the transplant of fecal matter. http://www.freakonomics.com/2011/03/04/freakonomics-radio-the-power-of-poop/ http://www.freakonomics.com/2011/03/04/freakonomics-radio-th... Memorably, they called a fecal transplant a "transpoosion".
__--__ 14y ago
For as logical a group as I perceive HN to be, any nutrition related article reminds me of the simple fact that most people can't assimilate new information when it conflicts with previously held mental models. For whatever reason, diet is something we get drilled into our head from the time we're very young. Even though most of it has been thoroughly debunked by scientific studies (cholesterol, the food pyramid, excessive cardio, saturated fat, wheat) people refuse to believe it. Every time, I see people trot out the same arguments (calories in/calories out seems an especially stubborn one). So, my question is this - How do we communicate new science in a way that will change people's minds? Or should I just be content that the next generation might stumble on this stuff through a web search before what they are taught in school firmly takes hold?

58 points by tokenadult 14y ago

The mouse studies, the C.fid studies, fascinating stuff. Would be a hell of a project to do flora studies. Perhaps we could blend it with Gate's new toilet initiative, press this button if you're you willing to enter a survey of gut flora and a chance to win an Amazon Gift card! Now please don't move while the swab extends ...

brianbreslin 14y ago

Could we see a legit probiotic capsule that is sold over the counter that has fat burning capabilities? so we identify the bacteria common in thin people and let fat people spend $$$ to acquire it?

gojomo 14y ago
I'd guess that the balance of bacteria depends more on whole-system factors, especially diet and personal chemistry/digestive-tract-structure. Unless a strain is completely missing, adding a few more of one kind might be unlikely alone to change the equilibrium. Now, if you knocked out the old strains with antiobiotics, the repopulation might be more sensitive to the small amounts first reintroduced. These studies of a wasting disease in Africe offer more hints of the interplay of gut microbiome, diet, and antibiotics: http://www.nytimes.com/2013/01/31/health/antibiotics-can-save-lives-of-severely-malnourished-children-studies-find.html http://www.nytimes.com/2013/01/31/health/antibiotics-can-sav...

jcampbell1 14y ago

Mouse studies always turn out to be a tease when it comes to weightloss. I say we skip all the probiotic piddling and go straight for human fecal transplants. Unfortunately, it is hard to get researchers and patients to agree to get an enema of someone else's poo.

OGinparadise 14y ago
Unfortunately, it is hard to get researchers and patients to agree to get an enema of someone else's poo. Money does wonders. And since we spend untold billions a year trying to lose weight or to mitigate it's side effects, the money is there. Even if we lost half an ounce a day, it would be roughly 10lbs a year. More than enough for most people.
gojomo 14y ago
It's not that hard when patients are suffering and the treatment works. Fecal transplants are already being done for other disorders, and patients are demanding it: http://www.nytimes.com/2013/01/17/health/disgusting-maybe-but-treatment-works-study-finds.html http://www.nytimes.com/2013/01/17/health/disgusting-maybe-bu...
daniel-levin 14y ago
http://en.wikipedia.org/wiki/Fecal_bacteriotherapy http://en.wikipedia.org/wiki/Fecal_bacteriotherapy Human fecal transplants already exist

SoftwareMaven 14y ago

I think this is a great example (well, counter-example) of how screwed up nutritional research has been. We spent the last 30 years trying to shoe-horn the low-fat-low-cholesterol-is-everything, when we had no idea how the body works. It is great to see research like this happening. I've followed nutrition for a long time as I've dealt with chronic weight problems, and things have gotten much more interesting (read: less parroting of the "party line" and more new research) in the last 5-8 years. It's unfortunate that so much time was lost, because it takes 10-15 years to go from mice to people. Now if we could only get some experiments with decent controls, so we can actually learn something.

cromulent 14y ago
This research has been around for 30 years. There was one case in the 70's where obese adults were given controlled calculated diets in a hospital and one of them gained weight anyway as her gut flora was so good at extracting nutrients. http://www.abc.net.au/science/articles/2011/05/10/3212802.htm http://www.abc.net.au/science/articles/2011/05/10/3212802.ht... Edit: Here's another link I found in one of my old comments from a week or two ago: http://www.ncbi.nlm.nih.gov/pubmed/17183312 http://www.ncbi.nlm.nih.gov/pubmed/17183312
- draven 14y ago
  Could it be that varied diets could prevent us (our intestinal bacteria) from getting too good at digesting a specific diet then?
- crusso 14y ago
  Yeah, and Atkins was talking about the insulin response in the 1970's... but he was mostly ignored (if not ridiculed) by the research community. The GP was entirely correct in stating that nutrition research has been "screwed up".
yummyfajitas 14y ago
It isn't screwed up. In broad strokes, we understand very well. Calories in - calories out = weight gain. This has been demonstrated in thousands of lab studies. That's about 85%. Now we are just figuring out details and special cases.

david_ar 14y ago

I really don't understand arguments like this - the problem is that some people have digestive systems that are "too" efficient, and so the "solution" is to cripple their ability to properly absorb nutrients. It seems rather wasteful.

anonymous 14y ago
Not quite. More like some people have "hoarding" digestive systems that refuse to let excess nutrients be expelled. I do agree that having people waste food is bad, but having unhealthy obese people is even worse.
geuis 14y ago
I don't know if you're thin or overweight. I'm fat, always have been. I'll admit to a past of bad eating habits that put me where I am. But the point is that we live with an excess of calories around us. If I have a certain kind of over-efficient gut bacteria helping me out, the survival mechanism in my situation supports the less-efficient variety. Too many calories, whatever their source, has a huge negative effect on my life.
OGinparadise 14y ago
It seems rather wasteful. Honestly who cares? It's not like the food saved will go to feed a starving kid in Africa or something. Food is rotting in warehouses already, so it' more of a logistics /distribution thing. That takes time to solve and is a totally separate issue from the medical one..of people dying and suffering from fat /obesity. Different groups can work on separate issues.
- king_jester 14y ago
  > That takes time to solve and is a totally separate issue from the medical one..of people dying and suffering from fat /obesity. AFAIK, studies about deaths correlated or caused by being fat have been totally debunked and had nothing to do with body weight in the first place. To that end, one does not die from being fat and being fat doesn't mean you are suffering (except for how people and society treats you as a fat person).

sambeau 14y ago

Does this suggest that maybe we should be sharing each other's poo to prevent our gut being dominated by a single bacteria? And does that suggest, maybe, that obesity is in some way partly caused by modern hygiene and hand-washing preventing this from happening 'naturally'? It seems ironic that, after decades of bleach and bacterial hand-wash, I might be 'cured' of my obesity by eating a capsule someone else's fecal matter.

adaml_623 14y ago
The one situation where a suppository is the preferred alternative?
b1daly 14y ago
More or less, yes:-) http://en.m.wikipedia.org/wiki/Fecal_bacteriotherapy http://en.m.wikipedia.org/wiki/Fecal_bacteriotherapy
brent_noorda 14y ago
Here's how to get rich quick: Open a Fecal Transplant Clinic. Let your clients choose from a pamphlet of slim & trim fecal source (I want that one), and for a modest fee they get the shape they want. People WILL pay for this shit (literally).

draven 14y ago

I read something similar recently (though the blog post itself is from 2008): http://phenomena.nationalgeographic.com/2008/10/06/human-gut-bacteria-linked-to-obesity/ http://phenomena.nationalgeographic.com/2008/10/06/human-gut... The whole gut bacteria thing is quite fascinating. It evolves depending on our diet. The intestinal flora of a fetus is boootstrapped with bacteria from his mother. Gut bacterias can get genes from ingested bacterias: http://phenomena.nationalgeographic.com/2010/04/07/gut-bacteria-in-japanese-people-borrowed-sushi-digesting-genes-from-ocean-bacteria/ http://phenomena.nationalgeographic.com/2010/04/07/gut-bacte... And this kind of symbiosis with bacterias is not limited to humans (the rumen of cows is filled with bacterias that break down normally undigestible components of grass such as cellulose.) I bet research on this symbiosis will produce lots of interesting results!

jacques_chester 14y ago

Before people get too excited, remember, correlation isn't causality (aside: I never thought I'd get to be that guy on HN who says that). It's just as possible that different microbial populations follow from obesity. Actually, it seems more likely that this is the case, given that the populations change after band surgery. And, as always, there is no biological mechanism so far discovered that transcends the conservation of energy and matter. Given how hilariously silly any thread on diet becomes on HN (because for some reason saying "net caloric balance is the sole predictor of long term average body mass" drives people nuts), I believe I will sit this out to avoid getting a severe case of XKCD386.

cromulent 14y ago
I'll bite. Net caloric balance is an important predictor, but not the sole predictor. That's why it "drives people nuts" - because it is not true. For example: http://www.newscientist.com/article/dn23127-abnormal-gut-bacteria-linked-to-severe-malnutrition.html http://www.newscientist.com/article/dn23127-abnormal-gut-bac...
Daniel_Newby 14y ago
> saying "net caloric balance is the sole predictor of long term average body mass" drives people nuts Because it is like saying that fuel combustion causes car crashes. And then smugly congratulating yourself about how you have solved a major public health problem by prescribing a fuel shortage. > It's just as possible that different microbial populations follow from obesity. In which case transplanting the skinny microbes to a stout animal would make no difference. The research in question shows it does.

ry0ohki 14y ago

They say this explains why gastric bypass works, but from what I've seen, people who get gastric bypass can only physically eat a few calories per day in the beginning without terrible consequences. Eventually you can eat more, and I've seen the weight go back, so I'm confused why it would be bacteria.

pygy_ 14y ago
They say it probably accounts for 20% of the weight loss. Outline of the experiment: Take a mouse model of human obesity. Divide your sample in three groups: * Gastric bypass * Sham surgery (fake bypass, the surgical equivalent of a placebo) * Sham surgery + caloric restriction. Observe gut flora change in the first group only. "Graft" some of the gut bacteria of the three groups in obese mice who didn't undergo surgery. Observe a moderate weight loss, only in the mice who received a stool sample of the first group. Here's the abstract: Roux-en-Y gastric bypass (RYGB) results in rapid weight loss, reduced adiposity, and improved glucose metabolism. These effects are not simply attributable to decreased caloric intake or absorption, but the mechanisms linking rearrangement of the gastrointestinal tract to these metabolic outcomes are largely unknown. Studies in humans and rats have shown that RYGB restructures the gut microbiota, prompting the hypothesis that some of the effects of RYGB are caused by altered host-microbial interactions. To test this hypothesis, we used a mouse model of RYGB that recapitulates many of the metabolic outcomes in humans. 16S ribosomal RNA gene sequencing of murine fecal samples collected after RYGB surgery, sham surgery, or sham surgery coupled to caloric restriction revealed that alterations to the gut microbiota after RYGB are conserved among humans, rats, and mice, resulting in a rapid and sustained increase in the relative abundance of Gammaproteobacteria (Escherichia) and Verrucomicrobia (Akkermansia). These changes were independent of weight change and caloric restriction, were detectable throughout the length of the gastrointestinal tract, and were most evident in the distal gut, downstream of the surgical manipulation site. Transfer of the gut microbiota from RYGB-treated mice to nonoperated, germ-free mice resulted in weight loss and decreased fat mass in the recipient animals relative to recipients of microbiota induced by sham surgery, potentially due to altered microbial production of short-chain fatty acids. These findings provide the first empirical support for the claim that changes in the gut microbiota contribute to reduced host weight and adiposity after RYGB surgery. http://stm.sciencemag.org/content/5/178/178ra41 http://stm.sciencemag.org/content/5/178/178ra41

shin_lao 14y ago

What happened to eating less?

segmondy 14y ago
people want to have their cake and eat it too.
epo 14y ago
Sshh, don't be insensitive, some people have a rare metabolic disorder.
- shin_lao 14y ago
  Sure. That's why one third of the USA is overweight. Probably a rare metabolic disorder. ;)

crusso 14y ago

Freakanomics had a good podcast on the subject of the healthful role of bacteria in the intestines. They covered the transplant of fecal matter. http://www.freakonomics.com/2011/03/04/freakonomics-radio-the-power-of-poop/ http://www.freakonomics.com/2011/03/04/freakonomics-radio-th... Memorably, they called a fecal transplant a "transpoosion".

__--__ 14y ago

For as logical a group as I perceive HN to be, any nutrition related article reminds me of the simple fact that most people can't assimilate new information when it conflicts with previously held mental models. For whatever reason, diet is something we get drilled into our head from the time we're very young. Even though most of it has been thoroughly debunked by scientific studies (cholesterol, the food pyramid, excessive cardio, saturated fat, wheat) people refuse to believe it. Every time, I see people trot out the same arguments (calories in/calories out seems an especially stubborn one). So, my question is this - How do we communicate new science in a way that will change people's minds? Or should I just be content that the next generation might stumble on this stuff through a web search before what they are taught in school firmly takes hold?