It's quite hard to actually overload your liver with the artificial sweeteners unless you are drinking literal gallons of zero sugar pop a day or eating nothing besides artificially sweetened foods. The stuff is used in such tiny concentrations that someone would have to deliberately seek out overdosing on this stuff to get the same effects as the experimental animals are getting (because the experimental animals are being fed pure sorbitol in doses that no human could reasonably consume.)

That's the problem with articles like this is that they don't emphasize that they are only seeing this in animal models and they don't disclose just how much of the stuff they had to give to the animal for the negative effects to occur. It's also a bad study because it doesn't account for the differences in the physiology and biochemistry between humans and zebrafish, nor does it account for the confounding factors in humans. You know who drinks and eats a lot of artificially sweetened things? People with diabetes and people who are trying to lose weight. These are people that are likely to already have fatty liver disease and the sorbitol didn't really have much to do with it.