I previously wrote about my experiences with glucose intolerance:

A study has now found:

Diabetes: The Sweetener Paradox


[T]he scientists adjusted the drinking water of the animals by adding the maximum recommended daily consumption dose of saccharin, aspartame or Sucralose. The control animals drank sugar water or unsweetened water. After eleven weeks, the researchers repeated the glucose tolerance test – with a clear result: during the experimental time period, all sweetener-drinking mice developed glucose intolerance, whereas none of the control mice did.

[...]

[T]he researchers administered high dosage of the broad-spectrum antibiotics ciprofloxacin and metronidazole, which act on Gram-negative bacteria, to both the leaner and obese animal subjects. During the antibiotic treatment, the animals continue to drink sweetener-containing water. Already after four weeks of therapy the researchers were barely able to detect glucose-intolerance test differences between the fatter and leaner animals drinking sweetener and the control animals. [...]

"These results suggest that the sweetener-induced glucose intolerance is caused by changes in the gut flora and the different proportions of its bacterial representatives”, the study authors conclude.

A further test was used to confirm this assumption: the scientists transferred the bacteria of the gastrointestinal flora of sweetener-drinking mice to microbe-free control mice. Already six days after the faecal transplant these mice were also suffering from glucose intolerance.

Original publication of study (Nature, September/October 2014):

Artificial sweeteners induce glucose intolerance by altering the gut microbiota