Fermented milks have been proposed to modulate gut transit time. Reduction of long transit times may be of importance in decreasing susceptibility to some large bowel diseases. Objective: to assess the effect on gut transit time in free-living elderly of a regular consumption of the milk fermented by the probiotic strain Bifidobacterium animalis DN-173 010 (108 CFU/g) and lactic acid cultures (108 CFU/g) (BM). Design: a randomized study was performed with 4 groups: 50 subjects with a stable transit time under 40 h (UTT: 24.6 h, SD = 1.7) and 50 subjects with a stable transit time over or equal to 40 h (OTT: 64.1 h, SD = 13.3) were included. Subjects from each transit group were randomly assigned to eat during 2 weeks, either 2 or 3 servings per clay of BM. The oro-fecal transit time was measured before and after BM consumption using a colored marker technique. Results: in the 4 groups, comparing values before and after BM consumption, the transit time reductions were statistically significant, being around 10% in UTT and around 40% in OTT (p < 0.001). ln UTT as well as in OTT, 3BM were more active than 2BM (p < 0.05). Conclusions: in elderly, the long gut transit times have been shortened by a 2-week regular consumption of the milk fermented with the strain Bifidobacterium animalis DN-173 010 and lactic cultures. This specific fermented milk can be considered as a functional food.