Bifidobacterium bifidum

Bifidobacterium bifidum (Tissier 1900) Orla-Jensen 1924 is the nomenclatural type species of the genus Bifidobacterium — the organism Tissier first described from the stools of breast-fed infants at the turn of the twentieth century under the name "Bacillus bifidus". The species reference strain, designated "Ti", is held as ATCC 29521 = DSM 20456 = JCM 1255 = CIP 56.7 = LMG 11041 and was itself isolated from the stool of a breast-fed infant. Unlike the lactobacilli it belongs to the phylum Actinomycetota, with a high-GC genome of roughly 2.2 to 2.3 Mb at about 62% G+C, and it appears microscopically as a pleomorphic, often branched or club-shaped rod rather than a plain bacillus. Bifidobacteria are strict anaerobes and ferment hexoses by the bifid shunt, routing fructose-6-phosphate through fructose-6-phosphate phosphoketolase to acetate and lactate. F6PPK activity is the classical diagnostic marker for the genus and is the assay used to confirm generic identity alongside molecular typing. What distinguishes B. bifidum within the genus is its carbohydrate strategy: it carries a battery of extracellular glycosidases for host mucin O-glycans, including endo-α-N-acetylgalactosaminidase (engBF) and 1,2-α-L-fucosidase (afcA), together with GH20 and GH84 β-N-acetylglucosaminidases. That is a compositional and enzymological fact about the organism, described here without any therapeutic implication. Commercially, B. bifidum is the least forgiving of the three common gut species to handle. It is markedly oxygen-, moisture- and heat-sensitive, and the difference between a specification met at release and a specification met at end of shelf life is almost entirely a question of how the powder was blended, encapsulated and packed. We supply it as a lyophilised live culture concentrate standardised on colony-forming units, as bulk powder or filled into HPMC or gelatin capsules, with overage set to hold label claim through the stated shelf life and a certificate of analysis per lot. Strain designation drives the dossier — MIMBb75, BB-06 (DSM 24688), R0071 and HA-132 are distinct commercial entities — so we quote against a named production strain and confirm its deposit number, identity and antimicrobial-resistance screening. Bifidobacterial fermentation media frequently carry milk-derived peptones or whey and, less often, soy, so allergen status is declared lot by lot and dairy-free grades are available. FSSAI requires a probiotic product to draw its organism from Schedule VII and to deliver at least 10⁸ CFU in the recommended daily serving unless a lower count is approved on evidence. We describe composition and viable count only, and make no therapeutic or disease claims.