Study evaluates impact of sugar substitutes in the human body

New research has found that non-nutritive sweeteners (NNS) can affect the human gut microbes and may alter glucose metabolism, though the effects may vary greatly among individuals.

The study, published in the journal, Cell, was conducted by researchers at the Weizmann Institute of Science in Rehovot, Israel. Investigators assessed NNS impacts in 120 healthy adults during a randomized-controlled trial.

During the study, researchers administered saccharin, sucralose, aspartame, and stevia sachets for two weeks in doses lower than the acceptable daily intake, compared with controls receiving sachet-contained vehicle glucose or no supplement.

They found that each administered NNS distinctly altered stool and oral microbiome and plasma metabolome, whereas saccharin and sucralose significantly impaired glycemic responses. In addition, researchers performed fecal transplantation of human microbiomes into germ-free mice and were able to demonstrate a causal and individualized link between NNS-altered microbiomes and glucose intolerance developing in non-NNS-consuming recipient mice, according to the study.

Overall, the study found human NNS consumption may induce person-specific, microbiome-dependent glycemic alterations, necessitating future assessment of clinical implications.

“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,” said Eran Elinav, MD, PhD, professor in Weizmann’s Systems Immunology Department and head researcher of the study, in a statement. “In fact, this variability was to be expected, because of the unique composition of each person’s microbiome. 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, it’s important to 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.”