Has an Alternative to Table Sugar Contributed to the C. Diff. And that’s not all: a diet containing trehalose significantly increased the severity of symptoms in a mouse model of C. diff. C. diff is a common bacterium that many people already have in their gut. These drugs can upset the normal balance of healthy gut microbes, and because C. diff. This shows the two C. diff strains have adapted to feed on trehalose in two completely different ways!