It's pretty clear to me that there is significant bias in the premise. Why, specifically, should it be artificial sweeteners that are toxic to gut bacteria? Iro

It's pretty clear to me that there is significant bias in the premise. Why, specifically, should it be artificial sweeteners that are toxic to gut bacteria? Irony is not a scientific motivation, it is a journalistic motivation. What makes artificial sweeteners more likely to be toxic to gut bacteria than, say, food coloring, preservatives, or (dare I say it) natural herbs and spices?