Posted on 09/06/2013 11:44:52 AM PDT by neverdem
What makes some people slender and others full-figured? Besides diet and genetics, the community of microbes that lives inside us may be partially responsible. New research on twins suggests that lean people harbor bacteria that their obese counterparts don't have. And, given the chance, those bacteria may be able to prevent weight gain. But don’t dig your skinny jeans out of the closet just yet. So far, the work has been done only in mice. What's more, the bacterial takeover requires a healthy, high-fiber diet to work, illustrating the complex relationship between diet, microbes, metabolism, and health.
Our intestines are home to at least 400 species of bacteria, and evidence is building that the balance of microbes in our internal ecosystem has far-reaching effects on health, including brain function and risk of cancer. A study last year showed that transferring gut bacteria between humans reduced insulin resistance, which is linked to obesity.
To explore how microbes differ between obese and lean people, researchers at Washington University in St. Louis took gut bacteria from four pairs of identical and fraternal twins; one sibling in each pair was lean and the other obese. Then they transplanted these microbes into mice that had no intestinal microbes of their own. The mice who got microbes from the lean twins stayed lean, the researchers report today in Science. Those that got microbes from the obese twins increased their body fat by 10% on average, even though they were eating the same amount of food.
What would happen if these two sets of microbes got mixed up in the gut, the researchers wondered. Led by microbiologist Jeffrey Gordon and graduate student Vanessa Ridaura, the team took advantage of one of the rodents' least endearing habits: They eat each other's poop. After letting this happen, the researchers discovered that microbes from the lean twins seemed to be particularly good at taking hold in the gut ecosystems of the mice that started with obesity-associated microbes. And after those bacteria moved in, the mice didn't gain weight. The most invasive species of microbes from the thin animals were in the Bacteroidetes group, which has previously been associated with leanness in mice and humans. The obese mice seemed to have unoccupied niches that the Bacteroidetes could easily move into.
To figure out what the gut bacteria might be doing, the researchers looked for bacterial genes that were active in the two kinds of mice. The heavier mice had higher levels of proteins involved in detoxification and stress responses; the lean mice expressed more genes involved in breaking down dietary fiber.
Diet, it turns out, was key to the impressive properties of the microbes from the lean twins. All the mice in the first round of experiments had been eating chow that was high in fiber and low in fat. The researchers then prepared a mouse-pellet form of an unhealthy human diet, high in fat and low in fiber, and housed svelte and heavy mice together again. They found that, with this diet, the microbes associated with leanness didn't colonize the cagemates’ intestines.
This work was rigorously done and fits in well with earlier findings, including the idea that Bacteroides may protect against weight gain, says Alan Walker, a gut microbiologist at the Wellcome Trust Sanger Institute in the United Kingdom who was not involved in the study. What's new here, he says, is that the researchers began addressing the question of how that protection might work: which species are responsible, what genes they use, and what diet they require.
"This study is an important step toward ultimately answering these questions," says microbiologist Peter Turnbaugh of Harvard University. A valuable result of this work, they both agree, is that it sets up a way to test the effects of microbial therapies on human gut bacteria (even though the bugs are living in a mouse). The authors suggest that a logical next step is to use the animals to measure the effects of particular foods or ingredients on gut ecosystems.
The mouse experiments also provide a way to test fecal transplants, which can cure a potentially fatal intestinal infection in humans and show potential for treating other conditions such as inflammatory bowel disease and obesity. There's a danger inherent in this approach: Transferring human feces into a patient's colon runs the risk of transmitting pathogens as well. Walker and the authors note that a well-tested "next-generation probiotic" consisting of known beneficial microbes delivered as a pill or other therapy could take the place of fresh feces, and this mouse system provides a way to identify the most effective bacteria, the diseases those bacteria can treat, and whether a particular diet is necessary.
"There's a major way to go before you can translate these results to humans," Walker cautions. A weight-loss probiotic isn't a simple next step, as the researchers found when they isolated 39 of the beneficial Bacteroidetes species. The mixture was unable to cause the same effects as mouse poop, possibly because the Bacteroidetes aren't acting alone and more of the microbial players need to be identified.
After Syria I think GayMuzzie will also be eating quite a bit of poop.
These scientists are full of you know what.
Socialism provides for lots of skinny people, too. Lots of them.
Gut bacteria?
At last - a business opportunity in my old age!
I’ve been long, lean, and healthy for 64 years.
However, I think my parents DNA deserves the credit more than I do.
Half of my lifelong diet has been chocolate candy, chocolate chip cookies, chocolate cake, and chocolate milkshakes (anyone see a basic theme here?).
Please don’t hate me, but I have consumed 3,000 to 4,000 calories a day since I was 18 years old.
I’m a lifelong runner, but exercise only metabolizes 1,000 calories a day.
The rest of it just.....disappears.
On the bacterial positive side, I eat lots of wheat germ, yogurt, and granola.
Will I be the first “poop pill” billionaire!
And maybe the reason we see the differences in how people respond to different diets is partly a matter of which strains of bacteria are established in their gut?
Good questions, maybe we'll have answers in human trials in a couple of years.
>>Their assumption that high-fat, low-fiber diets are unhealthy in humans is contradicted by numerous studies - and supported by numerous others. <<
It all depends on who is paying for the study as to what the answer will be.
Some microbes are happy in a mouse intestine where there is healthy, lean food, and other microbes prefer intestines where there is fatty food.
Moving the lean-loving bugs to an intestine with fatty food will cause the lean-loving bugs to die.
That much is science. Fanciful wishes and conclusions are not science.
I hate stupidity.
So will the rest of us.
So I should eat skinny people’s poop?
Any such condition that prevents certain (skinny) people from absorbing every available calorie would be a terrible genetic disadvantage, and would have been bred out of the population by all the periods of deprivation and famine.
I suppose maybe in addition to your hypothetical answer to the intelligent question: “So where do the calories go?” is that perhaps they are consumed by the bacteria (converted into heat energy?), whose waste products are non-caloric.
My observation (including myself most of all) is that caloric input, and energy output are the prime determinants (but for minuscule other factors) of obesity or the lack thereof.
Most of the secondary factors are have to do with conditions that cause people to want to eat more, or exercise less. Moreover, there are calories that are easier to eat, or easier to store, as compared to some formed of nutrients and dietary patters that presumably store poorly (leading to the “nutritious poop”) such as the Atkins/Ketosis effect.
If you have to eat somebody’s poop to catch something, I don’t know if that classifies as contagious.
We are a fat country
Just drove across it
Fat and trashy white people
No wonder Yankees here have no faith in woods anymore
Silly question. The amount of food (particularly fat-filled garbage) versus the amount of exercise (and, playing video games doesn't count!).
There's a lot in this area we don't know, and much in which the scientific studies are contradictory. But one thing is absolutely clear:
Obesity is not a simple matter of calories consumed vs. calories expended. People don't become obese because they eat too much and exercise too little. The metabolic disorders that cause obesity also cause lethargy and hunger.
(And there's nothing unhealthy about natural fat.)
Fine. :)
Were they watching the Human Centipede to get that idea?
(Don’t ever watch it)
it depends on the quality of the calories eaten, and if you’re spreading them across the day versus all at one time.
some people have a metabolism that runs hot.
Given all the idiotic weight loss products on the market, a pro-biotic yogurt for weight loss is on the saner, more scientific concepts.
(Reuters) - Celebrity trainer Bob Harper, of the weight-loss TV show “The Biggest Loser,” has built a career putting very obese people through some grueling fitness paces but if he’s learned anything from the experience, it’s that diet trumps exercise every time.
http://www.reuters.com/article/2013/08/22/us-fitness-trainer-bobharper-idUSBRE97L0Y320130822
You seem to be correct
I know that psyllium is used to add fiber, but what does bentonite do?
Ask anyone that was on Phen-Fen how they felt physically and whether they got hungry?
Problem was after a few month the body figured out it had been tricked, and put the weight back on.
There is no mystery involved in making people skinny, just starve them, they will lose weight.
The mystery is figuring out how to make money doing it.
I'm not sure that's true. Look at Asians and Africans as an example. It's rare to see an obese Asian, whether in Asia or in America. Most of them eschew the garbage diet that government meddlers and left-field "nutritionists" have cooked up for us. The same is true of Africans. Most Africans are thin, largely due to a diet that may depend on the available food supply and an ability to obtain any of it.
However, migrate to America and what happens? A vast majority of African-Americans become obese because they indulge in the crappy American diet of fast food, pizza and chips. However, Asians in America still tend to remain slim and healthy, largely because they retain the traditional Asian diet.
Finally, we have been inundated with "reserach" and "studies" that indicate that this or that is bad for us, only to be disproved by the next "research" or "study" that says "no, it isn't"! So, what are we supposed to believe? At the end of the day, I land on the side of moderation in everything. No fast food every day, no bags of chips and dip and sitting on my butt for hours at a time watching TV or working at a desk. If I need to talk to someone two doors over or even 3 floor up, I walk to their desk and give my phone a rest.
As a nation, we have become lazy and spoiled and accustomed to a diet of crap, garbage and massive calories, then we listen to idiots (like the FLOTUS) who tells us what we should eat (not that SHE keeps the same diet the rest of us are supposed to).
Way back in the olden days, schools taught courses like "Home Ec" that helped young women learn about nutrition and cooking/serving healthy foods. After the women's lib movement emerged in the late 60s, such courses were deemed "sexist" and were dropped from school curriculums. So, it's no wonder that we are a nation of obese people. With all the mixed messages and too many people choosing to eat out instead of preparing meals at home and fewer of us exercising outside, it's not a surprise we are a nation of obese people.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.