# Gut bacteria seem to play a role in obesity **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [September 4, 2013, 8:08am UTC](https://boards.straightdope.com/t/gut-bacteria-seem-to-play-a-role-in-obesity/667979 "2013-09-04T08:08:46Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![deltasigma](https://avatars.discourse-cdn.com/v4/letter/d/e5b9ba/32.png) [@deltasigma](https://boards.straightdope.com/u/deltasigma)\ **Post date:** [September 4, 2013, 8:08am UTC](https://boards.straightdope.com/t/gut-bacteria-seem-to-play-a-role-in-obesity/667979/1 "2013-09-04T08:08:46Z")
It’s well known that intestinal flora are important in a variety of ways for a variety of reasons but the exact [mechanisms are still being worked out](http://www.nlm.nih.gov/medlineplus/news/fullstory_140159.html) especially since the whole concept of a human microbiome is still relatively new. > [@](#): > > The research finds that “people who put on the most weight lack certain bacterial species or have them at very low levels. This opens ways to develop bacterial therapies to fight weight gain,” he said. > > Experts believe the gut, where the body processes food, is crucial to weight gain and weight loss. > > “It is now well known that bacteria in our gut play an important role in our health and well-being, possibly as important as our own immune response and proper nutrition,” said Jeffrey Cirillo, a professor at Texas A&M Health Science Center’s department of microbial pathogenesis and immunology. “This means that disruption of the bacteria in our gut by use of antibiotics or eating foods that help only particular bacteria grow can have effects upon our entire bodies.” > > A study released last March in the journal _Science Translational Medicine_ suggested that gastric bypass surgery led to weight loss – in mice – because it changed the makeup of the bacteria in their intestines. > > In one of the new studies, which are both published in the Aug. 29 issue of the journal _Nature_, researchers analyzed the gut bacteria of 169 obese Danish people and 123 Danish people who were not obese. > > The gut germs in the obese people were less diverse than in the others, and had more abnormalities in terms of metabolism. Also, obese people with a less diverse supply of germs gained more weight. ---
**Author:** ![Jackmannii](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jackmannii/32/311_2.png) [@Jackmannii](https://boards.straightdope.com/u/Jackmannii)\ **Post date:** [September 4, 2013, 12:21pm UTC](https://boards.straightdope.com/t/gut-bacteria-seem-to-play-a-role-in-obesity/667979/2 "2013-09-04T12:21:34Z")
One big question is whether less diverse gut flora _leads_ to obesity, or whether poor diet associated with obesity results in less diverse gut flora. ---
**Author:** ![phouka](https://avatars.discourse-cdn.com/v4/letter/p/c5a1d2/32.png) [@phouka](https://boards.straightdope.com/u/phouka)\ **Post date:** [September 4, 2013, 1:14pm UTC](https://boards.straightdope.com/t/gut-bacteria-seem-to-play-a-role-in-obesity/667979/3 "2013-09-04T13:14:03Z")
Either way, there’s every indication that a diverse gut biome is integral to good health, so it should be treated at least as a symptom of obesity, and that means looking at treatment. ---
**Author:** ![Dallas\_Jones](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dallas_jones/32/3277_2.png) [@Dallas\_Jones](https://boards.straightdope.com/u/Dallas_Jones)\ **Post date:** [September 4, 2013, 5:18pm UTC](https://boards.straightdope.com/t/gut-bacteria-seem-to-play-a-role-in-obesity/667979/4 "2013-09-04T17:18:37Z")
Fecal implants have been used very successfully to help patients with C-diff infections. Usually elderly people whose gut bacteria have been killed off by the various medications and antibiotic taken. This study from the Mayo Clinic shows a 90% success rate. [http://www.mayoclinic.org/medicalprofs/fecal-transplants-ddue1012.html](http://www.mayoclinic.org/medicalprofs/fecal-transplants-ddue1012.html) ---
**Author:** ![Hari\_Seldon](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hari_seldon/32/5173_2.png) [@Hari\_Seldon](https://boards.straightdope.com/u/Hari_Seldon)\ **Post date:** [September 4, 2013, 5:27pm UTC](https://boards.straightdope.com/t/gut-bacteria-seem-to-play-a-role-in-obesity/667979/5 "2013-09-04T17:27:18Z")
> [@Jackmannii](#): > > One big question is whether less diverse gut flora _leads_ to obesity, or whether poor diet associated with obesity results in less diverse gut flora. Or: “Correlation is not causation.” ---
**Author:** ![bump](https://avatars.discourse-cdn.com/v4/letter/b/7c8e57/32.png) [@bump](https://boards.straightdope.com/u/bump)\ **Post date:** [September 4, 2013, 6:04pm UTC](https://boards.straightdope.com/t/gut-bacteria-seem-to-play-a-role-in-obesity/667979/6 "2013-09-04T18:04:13Z")
> [@Dallas\_Jones](#): > > Fecal implants They really ought to come up with a better name; that sounds horrible any way I try to imagine those words. (even though I know what the procedure actually is). ---
**Author:** ![PSXer](https://avatars.discourse-cdn.com/v4/letter/p/48db29/32.png) [@PSXer](https://boards.straightdope.com/u/PSXer)\ **Post date:** [September 4, 2013, 6:21pm UTC](https://boards.straightdope.com/t/gut-bacteria-seem-to-play-a-role-in-obesity/667979/7 "2013-09-04T18:21:12Z")
I knew it wasn’t my fault ---
**Author:** ![deltasigma](https://avatars.discourse-cdn.com/v4/letter/d/e5b9ba/32.png) [@deltasigma](https://boards.straightdope.com/u/deltasigma)\ **Post date:** [September 4, 2013, 7:19pm UTC](https://boards.straightdope.com/t/gut-bacteria-seem-to-play-a-role-in-obesity/667979/8 "2013-09-04T19:19:51Z")
For people who think this NIH article is woo or that there’s nothing to be gained from the study of the microbiome, here’s a [short article from Time](http://science.time.com/2013/08/29/you-are-your-bacteria-how-the-gut-microbiome-influences-health/) you might want to read. > [@](#): > > One study, organized through the pan-European MetaHIT consortium, examined the bacterial genes present in the stool of nearly 300 Danish volunteers, both lean and obese, as well as markers of metabolic health. That team found that having a relatively low genetic diversity in one’s microbiome correlated with higher inflammation, greater insulin resistance and other warning signs of metabolic diseases. Obese participants who had low diversity also gained significantly more weight over the course of nine years, the team reported. > > The other study, from the ANR MicroObes consortium of researchers in France, put 49 French volunteers, all overweight or obese, on a low-calorie diet. Strikingly, the participants who had low genetic diversity in their microbiomes at the beginning saw their diversity increase and their metabolic markers improve on the diet. People who already had high diversity didn’t see nearly so much improvement, suggesting that perhaps a low-diversity microbiome, though linked to worse metabolic health, is amenable to dietary intervention. ---
**Author:** ![sparky\_1](https://avatars.discourse-cdn.com/v4/letter/s/77aa72/32.png) [@sparky\_1](https://boards.straightdope.com/u/sparky_1)\ **Post date:** [September 4, 2013, 8:18pm UTC](https://boards.straightdope.com/t/gut-bacteria-seem-to-play-a-role-in-obesity/667979/9 "2013-09-04T20:18:27Z")
They’re always studying the Danes. What makes those pasty people so special, is what I wanna know! Mmmm… _drool_ pasty pastry. ---
**Author:** ![CLee](https://avatars.discourse-cdn.com/v4/letter/c/f19dbf/32.png) [@CLee](https://boards.straightdope.com/u/CLee)\ **Post date:** [September 5, 2013, 4:43pm UTC](https://boards.straightdope.com/t/gut-bacteria-seem-to-play-a-role-in-obesity/667979/10 "2013-09-05T16:43:30Z")
> [@Jackmannii](#): > > One big question is whether less diverse gut flora _leads_ to obesity, or whether poor diet associated with obesity results in less diverse gut flora. This, isn’t it? Haven’t we already learned that diabetics are prone to fungal infections? Wouldn’t a high carb diet also provide fuel for the “bad” flora to flourish even in non-diabetics? It would be unsurprising to find that unreasonable carbohydrate cravings are the result of a thriving, ravenous population of sugar-loving gut flora garden cultivated by the very host himself. Michael Pollan touches on this topic a bit in his essay “Some of My Best Friends are Germs”: [http://www.nytimes.com/2013/05/19/magazine/say-hello-to-the-100-trillion-bacteria-that-make-up-your-microbiome.html?pagewanted=all&\_r=0](http://www.nytimes.com/2013/05/19/magazine/say-hello-to-the-100-trillion-bacteria-that-make-up-your-microbiome.html?pagewanted=all&_r=0) ---
**Author:** ![rhubarbarin](https://avatars.discourse-cdn.com/v4/letter/r/eb9ed0/32.png) [@rhubarbarin](https://boards.straightdope.com/u/rhubarbarin)\ **Post date:** [September 5, 2013, 8:08pm UTC](https://boards.straightdope.com/t/gut-bacteria-seem-to-play-a-role-in-obesity/667979/11 "2013-09-05T20:08:16Z")
My gut flora must be unusually diverse (skinny and can’t gain). 🙂 Or maybe, just inefficient. I also believe I have high levels of ‘brown fat’ which contribute to my being underweight. My basal metabolism isn’t particularly high from what I can tell - my weight as an adult has only varied by 5 lbs or so as an adult whether I am eating moderately and doing lots of cardio (such as now) or eating tons and either lifting heavy weights (in an attempt to bulk) or not exercising at all (during my lazy periods) - but when I overeat, my skin becomes hot to the touch, especially my chest, neck, and stomach. I get night sweats, and get restless and fidgety even in my sleep. I poop a lot more frequently. My entire system seems geared to rid itself of extra calories in every way except gaining weight. There’s no one factor that determines fat mass or bodyweight but we are learning more about the many factors that influence it every year. It’s so fascinating. ---
**Author:** ![Meatros](https://avatars.discourse-cdn.com/v4/letter/m/b4bc9f/32.png) [@Meatros](https://boards.straightdope.com/u/Meatros)\ **Post date:** [September 5, 2013, 8:21pm UTC](https://boards.straightdope.com/t/gut-bacteria-seem-to-play-a-role-in-obesity/667979/12 "2013-09-05T20:21:36Z")
> [@rhubarbarin](#): > > My gut flora must be unusually diverse (skinny and can’t gain). 🙂 Or maybe, just inefficient. > > I also believe I have high levels of ‘brown fat’ which contribute to my being underweight. My basal metabolism isn’t particularly high from what I can tell - my weight as an adult has only varied by 5 lbs or so as an adult whether I am eating moderately and doing lots of cardio (such as now) or eating tons and either lifting heavy weights (in an attempt to bulk) or not exercising at all (during my lazy periods) - but when I overeat, my skin becomes hot to the touch, especially my chest, neck, and stomach. I get night sweats, and get restless and fidgety even in my sleep. I poop a lot more frequently. My entire system seems geared to rid itself of extra calories in every way except gaining weight. > > There’s no one factor that determines fat mass or bodyweight but we are learning more about the many factors that influence it every year. It’s so fascinating. Yikes, that sounds horrible. When you are bulking, are you just eating a ton of food or are you eating something like 500 cals over maintenance? Also, you say you are strength training to bulk - are your weights going up? I guess I have a similar problem (night sweats and generally feeling like chit) when I, uh, ‘bulk’ (or rather, _over eat_), but I have no problem putting on weight. ---
**Author:** ![Meatros](https://avatars.discourse-cdn.com/v4/letter/m/b4bc9f/32.png) [@Meatros](https://boards.straightdope.com/u/Meatros)\ **Post date:** [September 5, 2013, 8:25pm UTC](https://boards.straightdope.com/t/gut-bacteria-seem-to-play-a-role-in-obesity/667979/13 "2013-09-05T20:25:18Z")
> [@Dallas\_Jones](#): > > Fecal implants have been used very successfully to help patients with C-diff infections. Usually elderly people whose gut bacteria have been killed off by the various medications and antibiotic taken. > > This study from the Mayo Clinic shows a 90% success rate. > > [http://www.mayoclinic.org/medicalprofs/fecal-transplants-ddue1012.html](http://www.mayoclinic.org/medicalprofs/fecal-transplants-ddue1012.html) I tried this a while ago, it turns out I had the procedure wrong. Not only did it not work, but I had terrible breath for the duration. ---
**Author:** ![voltaire](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/voltaire/32/313_2.png) [@voltaire](https://boards.straightdope.com/u/voltaire)\ **Post date:** [September 5, 2013, 9:26pm UTC](https://boards.straightdope.com/t/gut-bacteria-seem-to-play-a-role-in-obesity/667979/14 "2013-09-05T21:26:53Z")
Just happened to read [this article](http://www.theguardian.com/society/2013/sep/05/bacteria-slim-treat-obesity-study) right before seeing this thread: > [@](#): > > **Bacteria from slim people could help treat obesity, study finds** > > _Experiments show microbes from thin or fat people’s intestines can cause mice to lose or gain weight_ > > \ > > Researchers led by Jeffrey Gordon recruited four pairs of women who were twins. One woman in each pair was obese, but the other had a healthy body weight. > > From each woman, the researchers collected faeces which contained a wealth of expelled gut microbes. Through a number of tests, the scientists then investigated what happened when they transplanted these into mice bred to have no gut microbes of their own. > > The scientists found that mice stayed slim when they received faecal transplants from slim women, but put on much more fat when the samples came from the obese twin. Tests revealed that one type of bug, called Bacteroides, was more plentiful in slim women and protected the animals from putting on too much fat. > > In a follow-up experiment, mice with microbes from the slim women shared a cage with mice that had microbes from obese women. Because of the animals’ proclivity for coprophagia – that is their habit for eating each others’ poo – this caused a mixing of the animals’ gut microbes. > > After the mice had spent 10 days as cage mates, the obese ones had become more lean. But this only happened if the animals were fed a healthy diet that was high in fibre and low in saturated fats. When the diet was switched to high-fat, low-fibre meals the obese mice remained overweight. ---
**Author:** ![CLee](https://avatars.discourse-cdn.com/v4/letter/c/f19dbf/32.png) [@CLee](https://boards.straightdope.com/u/CLee)\ **Post date:** [September 5, 2013, 10:26pm UTC](https://boards.straightdope.com/t/gut-bacteria-seem-to-play-a-role-in-obesity/667979/15 "2013-09-05T22:26:29Z")
> [@voltaire](#): > > Just happened to read [this article](http://www.theguardian.com/society/2013/sep/05/bacteria-slim-treat-obesity-study) right before seeing this thread: Umm, don’t the subjects chosen for the study sort of disprove a genetic/organic cause of obesity? " Researchers led by Jeffrey Gordon recruited four pairs of women who were twins. One woman in each pair was obese, but the other had a healthy body weight." ---
**Author:** ![Yllaria](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/yllaria/32/3452_2.png) [@Yllaria](https://boards.straightdope.com/u/Yllaria)\ **Post date:** [September 5, 2013, 11:19pm UTC](https://boards.straightdope.com/t/gut-bacteria-seem-to-play-a-role-in-obesity/667979/16 "2013-09-05T23:19:21Z")
In most identical twin pairs, both twins stay within about twenty pounds of each other, even if separated at birth. So if it’s identical, rather than fraternal, twins that the study used\*, they’re not studying a typical situation. Obesity is not going to be a one-cause-fits-all thing. It’s also not going to be an everyone-has-the-same-cause thing. Even if genetic traits that can contribute are firmly identified, there will obviously also be things in the general or personal environment that contribute as well. I say obviously because there has been a sharp rise in obesity over too short a time for the entire cause to be genetic. - and it’s really sloppy of the writer not to specify identical or fraternal > [@bump](#): > > They really ought to come up with a better name; that sounds horrible any way I try to imagine those words. (even though I know what the procedure actually is). They’ll come up with a better name when it’s better understood and not nearly so home-brewed. Research is being done on which bacteria are probably doing the job, with the idea that a company could then rear and mix a cocktail of strains that have never seen the insides of anyone else’s colon. At that point, the treatment will get another name, and one or more products will get trademarked names designed by marketing consultants. Until then, the phrase is attention grabbing, so journalists aren’t going to drop it any time soon. ---
**Author:** ![deltasigma](https://avatars.discourse-cdn.com/v4/letter/d/e5b9ba/32.png) [@deltasigma](https://boards.straightdope.com/u/deltasigma)\ **Post date:** [September 5, 2013, 11:29pm UTC](https://boards.straightdope.com/t/gut-bacteria-seem-to-play-a-role-in-obesity/667979/17 "2013-09-05T23:29:16Z")
There are also epigenetic differences that are poorly understood at this point that won’t affect DNA coding but will determine whether genes are active or not. ---
**Author:** ![Hodge](https://avatars.discourse-cdn.com/v4/letter/h/5f9b8f/32.png) [@Hodge](https://boards.straightdope.com/u/Hodge)\ **Post date:** [September 5, 2013, 11:37pm UTC](https://boards.straightdope.com/t/gut-bacteria-seem-to-play-a-role-in-obesity/667979/18 "2013-09-05T23:37:47Z")
> [@bump](#): > > They really ought to come up with a better name; that sounds horrible any way I try to imagine those words. (even though I know what the procedure actually is). > [@Yllaria](#): > > They’ll come up with a better name when it’s better understood and not nearly so home-brewed. Research is being done on which bacteria are probably doing the job, with the idea that a company could then rear and mix a cocktail of strains that have never seen the insides of anyone else’s colon. At that point, the treatment will get another name, and one or more products will get trademarked names designed by marketing consultants. Until then, the phrase is attention grabbing, so journalists aren’t going to drop it any time soon. I prefer [RePOOPulate](http://www.uoguelph.ca/news/2013/01/post_229.html), myself. ---
**Author:** ![rhubarbarin](https://avatars.discourse-cdn.com/v4/letter/r/eb9ed0/32.png) [@rhubarbarin](https://boards.straightdope.com/u/rhubarbarin)\ **Post date:** [September 6, 2013, 2:53am UTC](https://boards.straightdope.com/t/gut-bacteria-seem-to-play-a-role-in-obesity/667979/19 "2013-09-06T02:53:55Z")
> [@Meatros](#): > > Yikes, that sounds horrible. When you are bulking, are you just eating a ton of food or are you eating something like 500 cals over maintenance? > > Also, you say you are strength training to bulk - are your weights going up? > > I guess I have a similar problem (night sweats and generally feeling like chit) when I, uh, ‘bulk’ (or rather, _over eat_), but I have no problem putting on weight. Basic maintenance (eat to appetite, no heavy exercise) seems to be 2000 for me. When I’m not using weights, I go back down to 102 lbs. If I’m exercising in addition to my usual active lifestyle (I work on my feet and cycle for transportation), 3000 is my usual diet, and it means I make myself feel not-quite-comfortably full twice a day. My weight never tops 108 lbs/my hip circumference never goes over 35.8. I have gone up to 4000 per day over weeks, but eating that much food makes me feel CRAPPY, and I give up before I can get over my usual limit. Of course if I could manage to overeat enough for long enough, I would put on weight, but my body protests so much it’s not worth it to me. This has all been true for the last 5 years. I don’t calorie count all that often but I’m both an eat to live person, and a health nut, so I eat basically the same things most days in measured portions. I count occasionally to make sure I am getting enough not to lose any weight as I don’t have a scale anymore. I like to keep myself at a minimum of 105lbs/35" hips which isn’t too hard. But I do have to work at it. My natural weight is 100-102lbs. ---
**Author:** ![brazil84](https://avatars.discourse-cdn.com/v4/letter/b/8491ac/32.png) [@brazil84](https://boards.straightdope.com/u/brazil84)\ **Post date:** [September 6, 2013, 6:04am UTC](https://boards.straightdope.com/t/gut-bacteria-seem-to-play-a-role-in-obesity/667979/20 "2013-09-06T06:04:39Z")
> [@voltaire](#): > > Just happened to read [this article](http://www.theguardian.com/society/2013/sep/05/bacteria-slim-treat-obesity-study) right before seeing this thread: Yes, I noticed it too. Unfortunately it looks like you need to subscribe to learn the details of the study. Assuming that the right gut bacteria give some protection from obesity, the question is how much of a difference does it make. I have a feeling that if you put a mouse on a “cafeteria diet” for a few months (i.e. the opportunity to eat as much varied junk food as it wants), then it will tend to get fat regardless of what bacteria it has in its gut. [Next page](https://boards.straightdope.com/t/gut-bacteria-seem-to-play-a-role-in-obesity/667979.md?page=2)