Health & Wellbeing

Gut microbes could offer weight loss benefits of GBP surgery – without the surgery

Gut microbes could offer weigh...
Gut microbes could provide weight loss benefits without surgery (Photo: Shutterstock)
Gut microbes could provide weight loss benefits without surgery (Photo: Shutterstock)
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Gut microbes could provide weight loss benefits without surgery (Photo: Shutterstock)
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Gut microbes could provide weight loss benefits without surgery (Photo: Shutterstock)

Gastric bypass (GBP) surgery has become a popular procedure for the treatment of morbid obesity. While many assume it is the reduction of the functional volume of the stomach that helps people feel fuller while eating less that is the solely responsible for the patient’s weight loss, it has been known for several years that there are other contributing factors at work. New research provides further evidence of this and could allow patients to see some of the weight loss benefits of GBP surgery without undergoing the surgery itself.

It is estimated there are around 100 trillion microorganisms in the human gastrointestinal tract. While people can live without them, research suggests the human/gut microorganism relationship is a mutually beneficial one, with the microorganisms doing everything from preventing the growth of harmful bacteria to producing vitamins for their host. Research has also shown differences in the microbial population – or microbiota – found in the gut of obese individuals (both mice and humans) and those in the gut of lean individuals.

Previous research has also shown that GBP surgery leads to changes in the gastrointestinal microbiota in humans and animals by resetting the balance between two types of bacteria. While some thought these changes might be a result of subsequent weight loss, researchers from Harvard University and Massachusetts General Hospital (MGH) have shown that the GBP surgery itself is directly responsible.

In experiments on mice, the researchers found that transferring samples of the altered microbiota from mice that had undergone GBP into mice raised in sterile conditions that hadn’t received surgery resulted in rapid weight loss in the germ-free mice.

“Simply by colonizing mice with the altered microbial community, the mice were able to maintain a lower body fat, and lose weight – about 20 percent as much as they would if they underwent surgery,” said Peter Turnbaugh, a Bauer Fellow at Harvard’s Center for Systems Biology.

This was despite the mice subjects being fatted up on a high-fat, high-sugar diet beforehand. “In some ways we were biasing the results against weight loss,” Turnbaugh said. “The question is whether we might have seen a stronger effect if they were on a different diet.”

While more study is needed to understand the underlying mechanism responsible for the weight loss, the research suggests it could one day be possible to provide some of the weight loss benefits of GBP surgery without actually performing the surgery itself.

"We need to learn a good deal more about the mechanism by which a microbial population changed by gastric bypass exerts its effects – including whether it contributes to the improvement in diabetes and other metabolic disorders we see in patients having the procedure – and then we need to learn if we can produce these effects, either the microbial changes or the associated metabolic changes, without surgery," explains Lee Kaplan, MD, PhD, director of the Obesity, Metabolism and Nutrition Institute at MGH and an associate professor of Medicine at Harvard Medical School.

"The ability to achieve even some of these effects without surgery would give us an entirely new way to treat the critical problem of obesity, one that could help patients unable or unwilling to have surgery," adds Kaplan

Kaplan and Turnbaugh are senior authors of the study that appears in the journal Science Translational Medicine.

Sources: Harvard University, Massachusetts General Hospital

13 comments
Freyr Gunnar
To lose weight, two things to try: - juicing : http://en.wikipedia.org/wiki/Fat,_Sick_and_Nearly_Dead
- banning corn syrup, which means junk food and pretty much all manufactured food these days : "Sugar: The Bitter Truth " www.youtube.com/watch?v=dBnniua6-oM
VirtualGathis
It's too bad they don't have a crowd-funding tool for research like this. I bet this one would be one of the projects that got blasted with donations. I can think of at least ten people I know who would gladly donate to this as they have been staring down the barrel of gastric surgery due to the utter failure of exercise and diet to effect weight loss.
OuldBill
Hmmmm- 20 percent means that for every 50 lbs. you'd lose by lap-band surgery, you could possibly lose up to 10 lbs. by this method - at least until your body re-adjusts to its 'natural' microbial balance, and you yoyo right back. Nope, there just ain't no substitute for informed self-control - and reasonable exercise.
ezeflyer
Elephants and other animals will sometimes eat their droppings in order to re-establish the normal intestinal biota.
JMOdom
@ Freyr Gunnar, and all of the rest who commented earlier.
I take it that none of you have never had an obesity problem. I’m 6 feet 3 inches tall (190.5 cm.) and weigh in at 400 lbs (181.4 Kg.) I was at 468 lbs. (212.3 kg.) at one time. I’ve tried exercise, eating healthy and cutting out surgar’s and sugary products. IT IS NOT AN EASY THING TO LOSE WEIGHT. If this procedure will work on humans I’m all for it. I’d love to be at about one-half the weight I am now.
Some of the suggestions I’ve read here are both offensive, rude and down right non-sensitive. Try wearing a bag with a bunch of bowling balls in them that double your weight and see how easy it is to try and do anything.
Garrett Ross
Or you could get off you butt and get active and eat right. I astounds me how many people are still looking for that miracle weight loss trend that will allow them to continue to eat processed foods and sit on their ass all day. I losses over 50 pounds by eating fresh food I prepared and mountain biking. A health diet and exercise works every time all the time, you just cant be lazy about it.
Bob Humbly
@JMOdom
Right on man, well said!
@ everyone else So high fructose corn syrup is the only cause for obesity? Explain buddha.
Pikeman
Many years ago the US Army did a test where they took healthy people and made one third eat normally as the control group, one third overeat, and one third under-eat. The group that overate gained an average of 50 pounds no matter how many excess calories consumed and when they went back to normal food consumption they lost the extra weight. The group that under-ate lost weight consistent with observed mass hunger events which include that a 20% reduction in calorie intake results in weight loss and a slowed metabolism that resulted in a 5-10 pound weight gain over their pretest weight upon returning to normal eating. The control group remained normal throughout.
The conclusion is that Anybody that is more than 75pounds overweight the cause is not overeating.
Slowburn
re; Bob Humbly
The obesity epidemic started at the same time as the introduction of high fructose corn syrup, and is not affecting nations that have banned high fructose corn syrup.
Also synthetic low calorie sweeteners link to gaining weight.
packoftwenty
Alternatively, overweight people could try eating less food and doing more exercise. What a crazy idea!