Khaberni - Health institutions have expressed increasing concern regarding the long-term effects of artificial sweeteners, which are substances used to provide a calorie-free sweet taste.
Despite appearing to be an ideal alternative to sugar, there are concerns that they may interfere with the metabolic process of energy, and increase the risk of diabetes and heart disease in the future.
Now, a new study conducted on mice has shown that common sweeteners "sucralose" and "stevia" have negative effects on gut microbiome and genetic expression, which may harm metabolic health, and more dangerously, these effects can be transmitted across generations.
Dr. Francesca Concha Silomi from the University of Chile, the lead author of the study published in the Frontiers in Nutrition journal, noted that despite the increasing consumption of these additives, rates of obesity and metabolic disorders such as insulin resistance have not decreased.
She explains that this does not mean that sweeteners are directly responsible for these trends, but it raises an important question about whether they affect metabolism in ways that science still cannot fully understand.
To conduct the study, scientists divided 47 mice into three groups, each receiving either plain water or water added with a dose of "sucralose" or "stevia", equivalent to the amount a human might consume as part of a regular diet.
These groups were then bred for three consecutive generations, although the subsequent generations were given only plain water, free of any sweeteners. Concha explained that animal models allow scientists to precisely control environmental conditions and isolate the effect of a specific factor such as a dietary compound, with the possibility to follow several generations in a relatively short period.
Each generation underwent an oral glucose tolerance test, which measures insulin resistance, an early warning sign of diabetes. Researchers also took fecal samples to detect changes in the gut microbiome and the concentration of short-chain fatty acids, which may indicate genetic changes transferable from parents to offspring.
In addition, scientists looked at the expression of five genes associated with inflammation and gut barrier function and metabolism in the liver and intestines, aiming to monitor the potential genetic effects that might explain the negative health impacts of non-nutritive sweeteners.
The researchers found that each sweetener had a different effect, and these effects changed over time across generations. In the first generation, only male offspring of mice that consumed "sucralose" showed signs of impaired glucose tolerance, but by the second generation, an increase in fasting blood sugar was discovered in male offspring of "sucralose" mice and female offspring of "stevia" mice.
Both groups that consumed sweeteners had more diverse fecal microbiomes, but with lower concentrations of short-chain fatty acids, indicating that beneficial bacteria were producing fewer beneficial metabolites, and this decrease continued in subsequent generations as well.
It seems that "sucralose" had the most significant and enduring impact, affecting the mice more severely, with more pathogenic and fewer beneficial types of bacteria in their feces.
"Sucralose" also appears to stimulate the expression of genes related to inflammation and reduce the expression of genes associated with metabolism, and these effects persist for two full generations after its consumption. "Stevia", although it also affects gene expression, its effects are smaller in magnitude and do not transfer to more than one generation.
Concha commented on these results by saying that the observed changes in glucose tolerance and gene expression can be interpreted as early biological signals associated with metabolic processes or inflammation, pointing out that the animals did not develop full diabetes, but showed mild changes in how the body regulates sugar and gene activity related to inflammation, which could increase susceptibility to metabolic disorders under certain conditions such as a high-fat diet.
