The present invention relates to: a novel Lactobacillus intestinalis YT2 strain (deposition number: KCCM11812P); and a composition for preventing, alleviating, or treating menopause, comprising, as an active ingredient, Lactobacillus intestinalis comprising the novel strain. The present inventors have established an animal model for menopause through ovariectomy, confirmed changes of the distribution of intestinal microorganisms by the model, identified and isolated a novel Lactobacillus intestinalis strain among lactic acid bacteria of which the distribution is significantly reduced in the menopausal model, and confirmed effects, by means of the novel strain and previously reported Lactobacillus intestinalis strains, of alleviating menopausal symptoms, such as the inhibition of an increase in body fat, the inhibition of a decrease in bone mineral density, the inhibition of an increase in the pain sensitivity, and the alleviation of depression. Therefore, it is expected that the composition comprising the Lactobacillus intestinalis according to the present invention can be usable for a use of preventing, alleviating, or treating menopause.