The world is facing a diabetes epidemic. A study reveals that the artificial sweeteners that people use to control diabetes could be exacerbating the epidemic. The researchers found that the chemicals change the composition and function of the microbes in the gut and hasten glucose intolerance and metabolic disorder. Even people who do not consume these sweeteners directly are exposed to the chemicals such as saccharin, aspartame, sucralose and Acesulfame K as they are part of processed foods.
The study published in the September 17 issue of Nature was led by Eran Elinav from the department of immunology of Weizmann Institute of Science in Rehovot, Israel. These researchers tested the impact of the chemicals by giving mice water laced with the three most commonly used artificial sweeteners (saccharin, sucralose or aspartame) – in amounts permitted by the FDA. They found that these mice developed glucose intolerance, while those that drank water or sugar water were healthy. The team repeated the experiment with different types of mice and different doses of the sweeteners and got the same results.
To investigate the role of gut microbiota in this glucose intolerance, the researchers treated mice with antibiotics to eradicate the gut bacteria. They found that this resulted in a full reversal of the artificial sweeteners' effects on glucose metabolism. When microbiota from mice that consumed artificial sweeteners was transferred to 'germ-free' mice, the recipient mice showed glucose intolerance.
The team then studied the effect of the sweeteners on human beings. They analysed the data from Personalized Nutrition Project, the largest human trial to date to look at the connection between nutrition and microbiota. They found linkage between self-reported consumption of artificial sweeteners, personal configurations of gut bacteria and the propensity for glucose intolerance.
They then conducted a controlled experiment and asked a group of volunteers who did not generally eat or drink artificially sweetened foods to consume them for a week and then undergo tests of their glucose levels as well as their gut microbiota compositions. Some of these volunteers developed glucose intolerance after just one week of artificial sweetener consumption. The chemical affected two different populations of human gut bacteria – one that induced glucose intolerance when exposed to the sweeteners, the second that had no effect either way. The researchers believe that certain bacteria in the guts of those who developed glucose intolerance reacted to the chemical sweeteners by secreting substances that then provoked an inflammatory response similar to sugar overdose, promoting changes in the body's ability to utilize sugar.
"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," says Elinav.