Eating a lot of sugar makes the gut more leaky in fruit flies and human gut cells in a lab setting, which can be seen when blue dye leaks out of the gut in flies or when a special dye passes through gut cells more easily.

The bacteria in the gut interact with sugar to affect how leaky the gut is in fruit flies and human gut cells in a lab setting.

Eating a lot of sugar makes a protective enzyme called intestinal alkaline phosphatase less active in fruit flies and human gut cells in a lab setting.

Eating a lot of sugar makes fruit flies have smaller guts and smaller bodies overall.