C. acnes has already been linked to elevated levels of neurotrophins related to the penetration of nociceptive neurons into the deeper layers of the annulus fibrosus in cell cultures [32] as well as to the stimulation of the expression of IL-1β and other molecules associated with disc degeneration, inflammation, neo-innervation, and the activation of pain pathways [32,45,46,47,48]. Here, BDNF is linked to intervertebral disk degenerative disorder.