Non-nutritive sweeteners alter microbiome function and glucose control, research finds

22 Aug 2022 --- Researchers are challenging the long-held belief that non-nutritive sugar substitutes have no impact on humans. They discovered that some sweeteners could modify consumers’ microbiomes, affecting blood sugar levels.

“In subjects consuming the non-nutritive sweeteners, we could identify very distinct changes in the composition and function of gut microbes and the molecules they secret into peripheral blood,” says Eran Elinav, senior study author and immunologist and microbiome researcher at the Weizmann Institute of Science and the German National Cancer Center.

This seems to indicate that each of these sweeteners affects the gut microbes in humans, he explains.

“When we looked at consumers of non-nutritive sweeteners as groups, we found that two non-nutritive sweeteners, saccharin and sucralose, significantly impacted glucose tolerance in healthy adults. Interestingly, changes in the microbes were highly correlated with the alterations in people’s glycemic responses.”

Expert reaction to findings
In an expert opinion on the study looking at how glycemic levels and human microbiomes are affected by non-nutritive sweeteners, Dr. Sarah Berry, senior lecturer at King’s College London, explains: “This study contributes to our current knowledge by providing evidence in humans at realistic intake doses that sweetener consumption impacts the microbiome composition and function, which has previously only been well studies in animal models.”

Non-nutritive sweeteners alter the composition and function of gut microbes. “This study confirms what has been previously shown in mice about the impact of sweeteners on the microbiome and adds to the body of evidence that some sweeteners have an unfavorable effect on blood glucose control,” adds Berry.

Determining impact on glycemic responses
Previously, researchers discovered that non-nutritive sweeteners impacted the microbiomes of mice in ways that might have changed the mice’s glycemic responses. 

To evaluate if these findings would be similar in human subjects, the research team in the current study screened over 1300 participants for those who strictly avoid non-nutritive sweets in their daily lives. They found a cohort of 120 people to answer this crucial question.

Six groups were created from these participants: two were controls, and four consumed amounts of aspartame, saccharin, stevia or sucralose that were much below the daily limits recommended by the FDA. The results unveiled that two non-nutritive sweeteners altered glycemic responses.

“In all of the non-nutritive sweetener groups, but in none of the controls, when we transferred into these sterile mice the microbiome of the top responder individuals collected at a time point in which they were consuming the respective non-nutritive sweeteners, the recipient mice developed glycemic alterations that very significantly mirrored those of the donor individuals,” Elinav explains.

To prove causation, the study subjects’ microbial samples were transferred to germ-free mice, which are raised in entirely sterile settings and lack their microbiomes.

Experts maintain that switching to foods with sweeteners (rather than sugar) is a method for a healthier and more balanced diet.“In contrast, the bottom responders’ microbiomes were mostly unable to elicit such glycemic responses,” he adds. “These results suggest that the microbiome changes in response to human consumption of non-nutritive sweetener may, at times, induce glycemic changes in consumers in a highly personalized manner.”

Tackling contradicting information
Non-nutritive sweeteners have been critically evaluated by international authorities and are safe and approved for use in a range of food and drink products, explains Sarah Coe, a nutrition scientist at the British Nutrition Foundation.

 “There is often contradictory information in the media about sweeteners’ safety and health effects, which can confuse consumers. The findings of this latest study add to the evidence suggesting an effect of the non-nutritive sweeteners sucralose and saccharin on the gut microbiome and the development of glucose intolerance.”

“This study does not indicate a need to change average consumption habits of non-nutritive sweeteners.”

“It’s important that the science on the long-term effects of non-nutritive sweeteners continues to be reviewed, and further research with more long-term, randomized controlled trials in humans are needed to investigate the potential effects of non-nutritive sweeteners on the gut microbiota and how this relates to health outcomes and disease risk,” adds Coe.

“Switching to foods with sweeteners (rather than sugar) is still one-way consumers can manage their daily calorie intake as part of achieving a healthier, more balanced diet.”

Previous sugar replacement moves
According to a previous study, a low-calorie sweetener created from mogrosides – a group of chemical compounds – and galactooligosaccharides may provide the same effects as artificial sweeteners without the disadvantages like increased appetite or weight gain while feeding a healthy gut.

Meanwhile, a separate study from the Ben Gurion University of the Negev in Israel found that artificial sweeteners could contribute to chronic digestive diseases and discomfort.

Considering sweetener alternatives, Sweegen introduced a blocking technology to lower the amount of sugar used in F&B applications while also utilizing the advantages of using antioxidants.

By Nicole Kerr