Noncaloric artificial sweeteners, such as Splenda, Sweet and Low, Equal were introduced in the hope to control body weight and lower risk for diseases linked to obesity. Yet the epidemic of type 2 diabetes and obesity seems to coincide with introduction of noncaloric sweeteners. Most of us assume that the epidemic of obesity and type 2 diabetes led to more use of noncaloric sweeteners. However, researchers in Israel report that the opposite might be true: Use of noncaloric sweeteners might have contributed to the epidemic.
Mice that are given noncaloric sweeteners develop glucose intolerance quickly, compared with mice that are given sucrose or glucose. Introduction of dietary noncaloric sweeteners promptly alters the mouse microbiome to favor biochemical pathways that enhance absorption of calorie-rich glucose and short-chain fatty acids. Giving antibiotics to the glucose-intolerant mice eliminated glucose intolerance, and transplanting feces from sweetener–fed animals into germ-free animals produced glucose intolerance in these control animals, whereas feces transplanted from glucose-fed mice into controls didn’t produce glucose intolerance.
Seven healthy human volunteers who did not regularly consume noncaloric sweeteners were placed on a diet that contained noncaloric sweeteners. Within 1 week, four participants developed glucose intolerance. Stool from these people, when transplanted to mice, also produced glucose intolerance. Stool from the three humans who did not develop glucose intolerance did not produce glucose intolerance in mice.
This report argues that, although artificial sweeteners lack calories, they can change the gut microbiome in a way that leads to absorption of more calories and that compromises glucose tolerance.
Suez J et al., Nature 2014 Oct 9; 514:181