Artificial sweeteners have always seemed like a win-win for dieters.Who doesn’t want to save a few calories by using an artificial sweetener such as saccharin (Sweet 'n Low), aspartame (Equal), or sucralose (Splenda)?

But artificial sweeteners may not be so win-win after all. You may be better off with the real deal — sugar — and simply limiting your consumption of sugar-sweetened foods and beverages. That's because artificial sweeteners appear to increase the risk of developing elevated blood sugar, or glucose intolerance, according to a recent study.

Artificial sweeteners may be causing the problems, such as glucose intolerance and diabetes, their use was intended to prevent.

The research on artificial sweeteners is mixed — some findings support their use and safety, while others indicate they may be dangerous and actually cause weight gain.

Israeli researchers say their findings suggest the use of artificial sweeteners should be reassessed because they may be causing the problems, such as glucose intolerance and diabetes, their use was intended to prevent.

Mice whose drinking water contained an artificial sweetener developed glucose intolerance, while mice drinking just water, or water with only sugar added, did not. Eran Elinav, an immunologist at the Weizmann Institute of Science, and his team found that non-caloric artificial sweeteners cause glucose intolerance by altering the balance of bacteria in the gut, bacteria that have been linked to an increased risk of metabolic disease.

Artificial sweeteners also changed the composition and function of the gut bacteria in four out of seven human volunteers. These microbial changes, in turn, contributed to glucose intolerance in these volunteers.

“What makes this study interesting is the questions it raises, rather than those it answers. The million-dollar question is why artificial sweeteners caused glucose intolerance and changed the gut bacteria, and not sugar,” Cathryn Nagler, a professor at the University of Chicago and the author of an editorial about the study, told TheDoctor.

“They are all biochemically different from each other, so why are they causing the same result?”

The researchers are currently recruiting participants for a larger study to look at the connection between gut bacteria and many common food products and the changes they cause that are linked to obesity, diabetes, and other diseases.

Elinav and Segal believe it is too early to make recommendations about the use of artificial sweetener use, but the findings have prompted Elinav to change his behavior.

“I’ve consumed very large amounts of coffee, and extensively used sweeteners, thinking like many other people that they are at least not harmful to me and perhaps even beneficial,” he said. “Given the surprising results that we got in our study, I made a personal [choice] to stop using them.”

The study and editorial are published online in Nature.