‘Artificial sweeteners induce glucose intolerance by altering the gut microbiota’
My colleagues and family pointed out a paper about the apparent effects of non-caloric artificial sweeteners in decreasing glucose tolerance that was published recently in Nature. I am not a dietician but the results interested me primarily because 1) I drink diet soda on occasion and 2) the key the the effect appears to be mediated by the microbiome.
Non-caloric artificial sweeteners (saccharin, sucralose and aspartame), consumed at levels approved of for human consumption, appeared to decrease glucose tolerance, a condition associated with type II diabetes, obesity and metabolic syndrome. This is a concern as many of us do not realize when we are using these sweeteners (diet sodas and diet desserts). The effect was caused by the microbiome, the bacteria that inhabit the gut. They also found that a significant shift took place in individual humans given normal doses of artificial sweeteners in as little as 7 days.
One of the most striking findings, for me, is shown above. Giving antibiotics to these mice significantly eliminated this glucose intolerance (shown as the height of the y axis here). This implies that bacteria are mediating the response. They also found that simply donating the microbes of mice who had been fed the high artificial sweeteners in their diet would cause glucose intolerance in the recipient organisms. The actual cause (outside of being microbial) is not yet known but the population shifts observed during consumption of these artificial sweeteners was similar to shifts associated with obesity. The researchers suggested that the bacteria that are encouraged to take up residence by non-caloric artificial sweeteners may be changing the way sugar is processed (more turned into fat cells) or may change insulin regulation in the blood of individuals.
Notably, in the human trial of 7 days, 4 of the 7 participants experienced dramatic shifts in microbiome and a decrease in glucose tolerance but 3/7 were non-responders. Medicine and nutritional advice may have to be tailored to individuals microbiome or genomes in the future. The latter may explain the variable results in artificial sweetener outcomes in the past.
You can hear my discussion with James Coleman on First@Five here: