It's interesting, but still a small sample size in a single country with potentially similar gut microbiomes. It would be much more meaningful to do the same study across different parts of the world and with a larger number of people. I think in some parts of the world it might be difficult to find enough people who don't consume any artificial sweeteners. If you never consume any and now take the test amounts, is that different than consuming it for many years? Could the effect of the test in people not continuously exposed to the sweeteners be different than those who use it routinely?