Sugar alternatives that offer sweetness without the calories can alter gut microbes and affect a person’s metabolic response to glucose, trial findings suggest.
Sucralose and saccharin impaired the glycemic response of healthy adults, according to the research in the journal Cell.
The calorie-free sweeteners affected different people in different ways, and further studies in mice revealed that glucose intolerance was driven by their individual impact on microbiome.
The microbiome are the microorganisms that live an environment such as a person’s body, and can include fungi, bacteria and viruses.
“Our trial has shown that non-nutritive sweeteners may impair glucose responses by altering our microbiome, and they do so in a highly personalized manner, that is, by affecting each person in a unique way,” summarized researcher Eran Elinav, a professor of systems immunology at the Weizmann Institute of Science in Rehovot, Israel, to Inside Precision Medicine.
“In fact, this variability was to be expected, because of the unique composition of each person’s microbiome.”
One of the most common dietary strategies to combat obesity and hyperglycemia has been to replace sugar with non-nutritive sweeteners such as saccharin, sucralose, aspartame, acesulfame-K, and stevia.
Noting nonetheless that the effect of this strategy remains uncertain, the researchers conducted a multi-arm, randomized controlled trial in 120 adults who strictly avoided non-nutritive sweeteners in their everyday lives.
Participants were divided into six groups and given either sachets of saccharin, sucralose, aspartame, and stevia sachets for 2 weeks in doses lower than the acceptable daily intake or assigned to control groups receiving the sachet-contained vehicle glucose or no supplement.
Each non-nutritive sweetener distinctly altered stool and oral microbiome and plasma metabolome, which is the study of small metabolite molecules.
Saccharin and sucralose significantly impaired glycemic responses, the research indicated.
The team then used fecal transplantation to transfer microbial samples from trial volunteers into germ-free mice that had been raised in sterile conditions and had no pre-existing microbiome.
When the mice received microbiome transfers from the top responders in the trial that were consuming their respective non-nutritive sweeteners, the mice developed glycemic alterations that significantly mirrored those of the donor human.
By contrast, transfers from the bottom responders in the trial mostly did not trigger these glycemic responses.
Elinav told Inside Precision Medicine: “The health implications of the changes that non-nutritive sweeteners may elicit in humans remain to be determined, and they merit new, long-term studies.
“In the meantime, we stress that our findings do not imply in any way that sugar consumption, shown to be deleterious to human health in many studies, is superior to non-nutritive sweeteners.”
