Consumption of fermented milk (FM) containing a probiotic, Lactobacillus gasseri SBT2055 (LG2055), previously showed a reduction in abdominal adiposity in a randomised controlled trial (RCT) using FM with 10(8) colony-forming units (cfu) of LG2055/g. However, whether the effectiveness is observed at lower concentrations, the recommended minimum or intermediate levels of probiotics (10(6) or 10(7) cfu/g, respectively), remains to be examined. A multi-centre, double-blind, parallel-group RCT was conducted using 210 healthy Japanese adults with large visceral fat areas (80·2 - 187·8 cm(2)). They were balanced for their baseline characteristics and randomly assigned to three groups receiving FM containing 10(7), 10(6) or 0 (control) cfu LG2055/g of FM, and were asked to consume 200 g FM/d for 12 weeks. Abdominal visceral fat areas, which were determined by computed tomography, at week 12, changed from baseline by an average of -8·5 % (95 % CI -11·9, -5·1; P< 0·01) in the 10(7) dose group, and by -8·2 % (95 % CI -10·8, -5·7; P< 0·01) in the 10(6) dose group. Other measures including BMI, waist and hip circumferences, and body fat mass were also significantly decreased from baseline at week 12 in both groups; interestingly, the cessation of taking FM for 4 weeks attenuated these effects. In the control group, none of these parameters significantly decreased from baseline. These findings demonstrate that consumption of LG2055 at doses as low as the order of 10(8) cfu/d exhibited a significant lowering effect on abdominal adiposity, and suggest that constant consumption might be needed to maintain the effect.