Written by Esther Kim

Are artificial sweeteners really healthy?

These days, many people are afraid of having sugar because of obesity and diabetes. So they take artificial sweeteners which are known for zero calories but taste the same as sugar. 

According to Nature, they discovered that the consumption of non-caloric artificial sweeteners induces changes in gut microbiota, which ultimately raises blood glucose levels and increases hemoglobin by using mice and humans experiment. From the rat experiment, it shows that blood glucose levels increase more when mice are given saccharin, sucralose, or aspartame (which are blue ones) compared to when they are given sugar (black one).

However, when blue ones are treated with antibiotics (antibiotic A in red, antibiotic B in gray), blood glucose levels drop lower than when consuming sugar. The result shows that there’s some connection with gut microbiota, since antibiotics killed gut bacterias.

Additionally, when the feces of mice that ate artificial sweeteners were transplanted to the normal mice, the normal mice’s blood glucose level increased. 

The picture shows that by consuming artificial sweeteners instead of sugar, it increases the levels of short-chain fatty acids (SCFAs) like acetate and propionate in the gut.

The most important thing in the gut environment is the balance of microorganisms. For our body to stay healthy, the microbial balance must be well-maintained. However, if we consume artificial sweeteners instead of glucose, microorganisms that help short-chain fatty acids like acetate and propionate increase in our gut. 

Why is this bad? Consuming a lot of artificial sweeteners leads to overgrowth of the microorganisms that absorb acetate and propionate, and they disrupt the balance and change the metabolic pathways of the gut microbiota. Consequently, the abundant short-chain fatty acids are used as our energy source instead of glucose by the altered pathways. In the end, our body compensates for the calories not from sugar but from short-chain fatty acids. Therefore, consuming artificial sweeteners does not reduce caloric intake.

The claim that artificial sweeteners alter the gut microbiota, disrupt balance, and do not reduce calorie intake has scientific support, still it remains controversial and requires further research. And The effects of artificial sweeteners can vary based on individual genetic background, lifestyle, and dietary habits.

Citation:

Suez, J., Korem, T., Zeevi, D. et al. Artificial sweeteners induce glucose intolerance by altering the gut microbiota. Nature 514, 181–186 (2014). https://doi.org/10.1038/nature13793