Weight Loss
Slim Down with Fiber
Resistant starch, a special type of fiber, leads to measurable weight loss without calorie reduction. A new study reveals: the right bacterial strain in your gut is the key to better health.
Weight Loss
Resistant starch, a special type of fiber, leads to measurable weight loss without calorie reduction. A new study reveals: the right bacterial strain in your gut is the key to better health.
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If you think fiber is old news and everyone already knows it's healthy and somehow helps with weight loss… not so fast! We have news for you. What we're sharing with you today is new knowledge—published just this year in the prestigious journal Nature Metabolism.1
A now-famous fiber that occurs naturally in foods but can also be synthetically manufactured is resistant starch. It is composed of the same building blocks as regular starch—which we know by the umbrella term "carbohydrates"—but cannot be broken down by human digestive enzymes in the small intestine.
So it enters the colon undigested, where bacteria living there immediately pounce on it. They really love such fibers.
But let's get straight to the effects. In rodents, researchers had already observed that resistant starch, unlike digestible starch, leads to a reduction in body fat. In the gold-standard study mentioned above, this could now be demonstrated in humans.
Overweight participants were divided into two groups. One group received resistant starch (RS) derived from corn, while the other received regular corn starch. Calories were equalized, and the meals both groups received daily were identical and isocaloric.
Remarkably: The RS group lost an average of 2.8 kg in eight weeks. Mind you, without calorie restriction. It was primarily fat mass that was lost, while the control group showed no change in body weight.
But weight loss wasn't the only impressive finding: RS improved our cells' ability to take up glucose (glucose tolerance), the integrity of the intestinal barrier (= less leaky gut), and reduced blood inflammation markers.
More specifically, a particular bacterial strain called Bifidobacterium adolescentis. This was one of three strains that, according to microbiome analysis, appeared more frequently in the colon of participants after consuming resistant starch. B. adolescentis showed the strongest correlation with reduced BMI, waist circumference, and visceral fat mass.
To determine whether the altered gut flora caused by RS was actually responsible for the weight-reducing effects, researchers conducted a microbiome transplant. Specifically, this meant: They had mice drink prepared human feces. It sounds gross, but it was effective: These mice also lost body fat without eating less and simultaneously improved their inflammation markers.
That the strain B. adolescentis was indeed the main driver of fat loss and improved glucose tolerance became clear when researchers compared mice that drank either just saline or the living bacteria. Again, the latter showed significantly better metabolic health. Sensational!
Swallow one bacterium and become metabolically healthier... That's pretty cool, right?
Not so cool, however, is that the positive effects disappeared four weeks after stopping the RS. In terms of weight and fat mass, participants were back to nearly their baseline level from before the study.
This means: To keep B. adolescentis alive, you should regularly consume resistant starch.
