TABLE 2.

Recent correlative studies on the effects of P. acnes on IDD.

References	Journal	Results
Chen et al., 2016	BioMed Research International	P. acnes causes Modic-1 changes and disk degeneration
Yuan et al., 2017	BioMed Research International	P. acnes was absolutely confirmed to be present in some nonpyogenic degenerated intervertebral disks, at a prevalence of approximately 21.05%.
Lin et al., 2018	Emerging Microbes & Infections	P. acnes-induced apoptosis of NPCs via the TLR2/JNK pathway is likely responsible for the pathology of IDD.
Ahmed-Yahia et al., 2019	PLOS ONE	P. acnes is present in both the IDD and the IVD
Tang et al., 2021	Oxidative Medicine and Cellular Longevity	P. acnes induces NPC pyroptosis via the ROS-NLRP3 signaling pathway, and the pyroptotic NPCs cause an IDD cascade.
Lan et al., 2022	PLOS ONE	P. acnes is widespread in herniated disk tissues.
Magno da Rocha et al., 2023	PLOS ONE	P. acnes causing IDD and its association with LBP.

P. acnes, Propionibacterium acnes; NPCs, nucleus pulposus cells; TLR2, Toll-like receptor 2; JNK, c-Jun N-terminal kinase; IVD, intervertebral disk; IDD, intervertebral disk degeneration; LBP, low back pain; IDD, intervertebral disk degeneration.