Artificial sweeteners might be triggering higher blood-sugar levels in some people and contributing to the problems they were designed to combat, such as diabetes and obesity, according to new findings published Wednesday in the journal Nature. Researchers suspect that artificial sweeteners could be disrupting the microbiome, a vast and enigmatic ecosystem of bacteria in our guts. In a series of experiments, researchers found that several of the most widely used types of non-calorie sweeteners in food and drinks - saccharin, sucralose and aspartame - caused mice to experience increased risk of glucose intolerance, a condition that can lead to diabetes. The same scientists also monitored what happened to seven human volunteers who did not typically use artificial sweeteners but were given regular doses of saccharin over the course of a week. Four developed significant glucose intolerance. Separately, the researchers analyzed nearly 400 people and found that the gut bacteria of those who used artificial sweeteners were noticeably different from people who did not. [These] findings add an intriguing new dimension to the long-running, contentious debate over the potential health benefits and risks of artificial sweeteners, which are among the most common food additives and are consumed by hundreds of millions of people around the globe. Other research has suggested that certain artificial sweeteners might actually contribute to obesity and other problems, including cancer. Perhaps no sweetener has proven more controversial than saccharin, which was discovered not long after the end of the Civil War. In 1977, the FDA tried to ban saccharin because of safety concerns after studies showing that rats had developed bladder cancer after receiving high doses of the chemical sweetener. Congress blocked that effort.