Bifidobacterium
Japanese: ビフィズス菌（Bifidobacterium属）
Anaerobic beneficial bacteria abundant in the human gut. They produce lactic acid and acetic acid to maintain intestinal health, and are particularly dominant in infant gut microbiota.
Bifidobacterium are anaerobic bacteria abundant in the human large intestine. They produce lactic acid and acetic acid, keeping the gut mildly acidic and suppressing harmful bacterial growth.
In a newborn's gut, Bifidobacterium dominate the microbiota. This is because oligosaccharides in breast milk serve as their food source.
Often confused with lactic acid bacteria, they are taxonomically a separate group. Their name derives from the Latin 'bifidus' (forked), reflecting their distinctive Y-shaped morphology.