American scientists wrote in the latest issue of cell magazine that saccharin and sucralose, two artificial sweeteners, may hinder the ability of human body to regulate blood sugar level after eating, possibly because sweeteners can induce some changes in intestinal microorganisms. In the latest study, YOTAN Suez of Johns Hopkins University and his colleagues tested the effects of four sugar substitutes on blood glucose in 120 adults without potential health conditions in Israel. Subjects were divided into 6 groups and provided with 1 g of sweetener. Within two weeks, participants in the four groups ate two packets of aspartame, sucralose, saccharin or Stevia dissolved in water three times a day, and all sweetener packets contained at least 96% glucose. The total daily consumption dose of each sweetener was lower than the acceptable daily intake determined by the U.S. Food and drug administration. The fifth group ingested the same amount of glucose powder, and the last group was not supplemented with any sweetener. Throughout the study, all participants wore continuous blood glucose monitors and completed glucose tolerance tests at 9 time points to measure the effectiveness of the body in controlling blood glucose levels after glucose intake. The researchers found that after the glucose tolerance test, the blood sugar of the people who ate saccharin and sucralose increased significantly, and the blood sugar of the other groups remained stable or even slightly decreased, indicating that it was not the glucose in the sweetener package that increased the blood sugar level. Analysis of the participants' daily stool and saliva samples showed that all four sweeteners significantly changed the number, activity and type of bacteria in the gut and oral cavity. They also collected blood samples every week and found corresponding changes in metabolites or molecules. Some blood metabolite changes in saccharin and sucralose groups were also seen in patients with diabetes or vascular diseases. The research team also transplanted fecal samples of people who ate saccharin, sucralose, glucose and no supplements to the digestive tract of mice, and found that feces transplanted from saccharin and sucralose groups led to increased postprandial blood glucose in mice. Suez said that this indicates that changes in microorganisms have led to this result. The sweetener itself does not increase blood sugar, but it seems to weaken the ability of the human body to control blood sugar levels after eating through a mechanism mediated by microorganisms. (outlook new era)