Studies on Mice Suggest That Bacterial Species Predominating in Obese

Studies on mice suggest that bacterial species predominating in obese individuals differ from those in the digestive tracts of lean individuals and that they play a role in weight gain in obese individuals. What are these bacteria in obese individuals proposed to do that increases weight gain in obese individuals?

A) They make obese mice eat more food.
B) They release chemicals that increase the caloric intake by the mice.
C) The bacteria in obese individuals may release more calories from digested food than their counterparts in leaner individuals.
D) The bacteria in obese individuals turn the food in the intestines to fat.
E) The bacteria in obese individuals produce gas that makes their hosts obese.