In patients with traumatic brain injury, studies using combinations of B. longum, L. acidophilus, L. bulgaricus, E. faecalis, and S. thermophilus showed reduced inflammatory cytokines such as IL-6, interferon-gamma (IFN-γ), or tumor necrosis factor-alpha (TNF-α), alongside improved immune responses, enhancing immune functioning and decreasing the incidence rate of complications [202,203,204]. Here, IFNG is linked to injury.