Artificial Sweeteners May Destroy the Gut Flora, Study Suggests

Sharon Moore September 25, 2014

The widespread use of artificial sweeteners in drinks and food may be contributing to the obesity and diabetes epidemic that is sweeping much of the world – new research says.

For years researchers have been puzzling over the fact that non-caloric artificial sweeteners do not seem to assist in weight loss, and some studies have suggested they may even have an opposite effect. The new findings, published in the journal Nature, suggests that artificial sweeteners, promoted as aids to weight loss and diabetes prevention, could actually hasten the development of glucose intolerance and metabolic disease; and they do it in a surprising way: by changing the composition and function of the gut microbiota – the substantial population of bacteria residing in our intestines.

Glucose intolerance – generally thought to occur when the body cannot cope with large amounts of sugar in the diet – is the first step on the path to metabolic syndrome and adult-onset diabetes, researchers explain.

For the study, the scientists gave mice water laced with the three most commonly used artificial sweeteners – in the equivalent amounts to those permitted by the FDA. These mice developed glucose intolerance, as compared to mice that drank water, or even sugar water. Repeating the experiment with different types of mice and different doses of the sweeteners produced the same results – these substances were somehow inducing glucose intolerance.

Then, they investigated a hypothesis that the gut microbiota are involved in this phenomenon. They thought the bacteria might do this by reacting to new substances like artificial sweeteners, which the body itself may not recognize as "food." Indeed, artificial sweeteners are not absorbed in the gastrointestinal tract, but in passing through they encounter trillions of the bacteria in the gut microbiota. More alarmingly, incubating the microbiota outside the body, together with artificial sweeteners, was sufficient to induce glucose intolerance in the sterile mice. A detailed characterization of the microbiota in these mice revealed profound changes to their bacterial populations, including new microbial functions that are known to infer a propensity to obesity, diabetes and complications of these problems in both mice and humans.

Eran Elinav of the Weizmann Institute’s Immunology Department, who led this research, said "Our relationship with our own individual mix of gut bacteria is a huge factor in determining how the food we eat affects us. Especially intriguing is the link between use of artificial sweeteners – through the bacteria in our guts – to a tendency to develop the very disorders they were designed to prevent; this calls for reassessment of today’s massive, unsupervised consumption of these substances."

Source of this article: Artificial sweeteners induce glucose intolerance by altering the gut microbiota, Nature