Bifidobacteria are friendly bacteria, colonizing mainly the large intestine, or colon. Bifidobacteria are considered extremely important to the health of the gastrointestinal tract. The bifidobacteria have been used to address intestinal disorders, and boost the immune system. These strains are also important for the production of B vitamins. Bifidobacteria may also reduce antibiotic-induced fluctuations in intestinal bacteriavii and the GI distress that can ensue.viii Antibiotics are particularly effective at killing all kinds of bacteria, good and badâ€”often leading to secondary infections. Bifidobacterium bifidum is especially good at enhancing the bodyâ€™s immune response and inhibiting harmful enzymes.ix Bifidobacterium longum has a high affinity for intestinal colonizationx, improving the intestinal environment, which leads to better regularity.