Researchers at the Weizmann Institute in Israel gave 120 healthy adults saccharin, sucralose, aspartame or stevia for two weeks, at doses below the official safe daily limit, and compared them against people given a sugar or no supplement at all.
Saccharin and sucralose measurably impaired glucose tolerance within two weeks, and each sweetener reshaped the bacteria living in the gut and mouth in its own distinct way. When the team transferred stool from top and bottom responders into germ-free mice, the mice's blood sugar reactions largely matched their human donor's.
The effect was person-specific rather than universal: some people's blood sugar barely moved, while others shifted substantially, tracking with how their particular gut bacteria responded to each sweetener. The trial lasted only two weeks in otherwise healthy adults, so it does not show what years of sweetener use do, or settle whether the blood sugar changes carry any real health consequence.
Read the original study
Suez et al., Cell, 2022 · doi.org/10.1016/j.cell.2022.07.016
Two weeks of sweetener, and the gut answered differently.
Source
- Suez, J., Cohen, Y., Valdés-Mas, R., Mor, U., Dori-Bachash, M., Federici, S., Zmora, N., Leshem, A., Heinemann, M., Linevsky, R., Zur, M., Ben-Zeev Brik, R., Bukimer, A., Eliyahu-Miller, S., Metz, A., Fischbein, R., Sharov, O., Malitsky, S., Itkin, M., . . . Elinav, E. (2022). Personalized microbiome-driven effects of non-nutritive sweeteners on human glucose tolerance. Cell, 185(18), 3307–3328.e19. https://doi.org/10.1016/j.cell.2022.07.016