This research paper explores how Bifidobacterium This research paper explores how Bifidobacterium bifidum (Bifidobacterium) improves oestrogen-deficiency-induced osteoporosis in mice by modulating intestinal immunity. The researchers used two Bifidobacterium strains (B. bifidum FL228.1 and B. animalis subsp. Lactis F1-7), both of which have been shown to reduce intestinal inflammation.