Fig. 4

Gut microbes from obese donors lead to excessive motivation for food reward. Operant conditioning test showing a the number of active lever presses and b the number of pellets earned during the progressive ratio sessions (PR) by lean (Lean_do) and diet-induced obese donor mice (DIO_do). Operant conditioning test showing c the number of active lever presses and d the number of pellets earned during the progressive ratio sessions (PR) by gut microbiota recipient mice from lean (Lean_rec) and obese donors (DIO_rec). Data are shown as mean ± SEM (n=6/group). p-values were obtained after unpaired Student’s t test. *: p-value ≤ 0.05; ** : p-value ≤ 0.01; *** : p-value ≤ 0.001; **** : p-value ≤ 0.0001