Obesity treatment using probiotics, composition for reducing body fat, and composition for reducing waist circumference

A method of selecting a responder to probiotic bacteria having an anti-obesity action comprising:

• (1) administering probiotic bacteria having the anti-obesity action to more than one subject;
• and
• (2) classifying the more than one subject into groups (c) and (d), wherein group (c) subjects have a high value ratio of the phylum Firmicutes to the phylum Bacteroidetes, and the group (d) subjects are all those not belonging to the group (c), wherein said classifying is by measuring composition ratios of intestinal flora of the subject at a phylum level.

A composition for reducing waist circumference, which contains Bifidobacterium and/or lactobacilli as an active ingredient, and is used administered to a pre-obese group of subjects or an obese group of subjects.