Specific bacteria in the gut could lead to metabolic changes after exposure to artificial sweeteners, a new study shows. The study indicates that ingesting artificial sweeteners, which are promoted as ways to assist in weight loss and diabetes prevention, can help to change the composition and function of bacteria in the gut, with a large portion of the bacteria residing in the intestines. These study findings, resulting from experiments in mice and humans, were published in the September 17, 2014 edition of Nature.

Dr. Eran Elinav of the Weizmann Institute’s Immunology Department, who helped to lead the research in conjunction with Professor Eran Segal of Computer Science and Applied Mathematics Department, noted that widespread use of artificial sweeteners in drinks and food could be helping to contribute to the global obesity and diabetes epidemic.

Over the years, researchers have been stumped by the fact that non-caloric artificial sweeteners do not seem to help with weight loss, with some studies suggesting that they may have the opposite effect. Jotham Suez, a graduate student who led the study, worked with other graduate students Tal Korem and David Zeevi in Segal’s lab and Gili Zilberman-Shapira in Elinav’s lab in finding that despite not containing sugar, artificial sweeteners directly impact the body’s ability to use glucose. Glucose intolerance is the initial step towards metabolic syndrome and adult-onset diabetes.

Segal said in a statement, “The results of our experiments highlight the importance of personalized medicine and nutrition to our overall health. We believe that an integrated analysis of individualized ‘big data’ from our genome, microbiome and dietary habits could transform our ability to understand how foods and nutritional supplements affect a person’s health and risk of disease.”

According to the American Diabetes Association, in 2012 29.1 million Americans, or 9.3 percent of the population, had diabetes.