I can’t help but think (other than being annoyed the studies aren’t linked right there) that it’s more of a correlation than causation that the artificial sweeteners are changing gut bacteria . Presumably you gut is adapt to high sugar intake, then all the sudden you’re not getting high sugar intake? Wouldn’t you expect these changes regardless of the artificial sweetener and wouldn’t the short term changes be basically a withdrawal from high amounts of table sugar which would be hard on the body in the short term but better off in the long term?