Lacticaseibacillus rhamnosus MG4706 Suppresses Periodontitis in Osteoclasts, Inflammation-Inducing Cells, and Ligature-Induced Rats.

Periodontitis is a chronic inflammatory disease characterized by tooth loss due to inflammation and the loss of alveolar bone. Periodontitis is closely related to various systemic diseases and is emerging as a global health problem. In this study, we investigated the anti-inflammatory effect of lactic acid bacteria (LAB) in vitro on Porphyromonas gingivalis ( P. gingivalis ) LPS-activated RAW264.7 and human gingival fibroblasts-1 (HGF-1) cells and the anti-osteoclastogenic effect of LAB on RANKL-induced RAW264.7 cells. All LAB strains ( Lacticaseibacillus rhamnosus MG4706, MG4709, and MG4711) inhibited nitric oxide (NO)/ inducible nitric oxide synthase ( iNOS ) in P. gingivalis LPS-activated RAW264.7 cells and pro-inflammatory cytokines ( IL-1β and IL-6 ) and matrix metalloproteinase ( MMP-8 and MMP-9 ) in HGF-1 cells. In addition, LAB treatment inhibited osteoclastogenesis by reducing tartrate-resistant acid phosphatase (TRAP) activity and cathepsin K ( CtsK ) through the downregulation of nuclear factor of activated T cells cytoplasmic 1 ( NFATc1 ) and c-fos gene expression in RANKL-induced RAW264.7 cells. Administration of MG4706 alleviated alveolar bone loss indices and reduced the gene expression of IL-1β , IL-6 , MMP-8, MMP-9, and RANKL / OPG ratio in gingival tissue. In conclusion, L. rhamnosus MG4706 has the potential to alleviate periodontitis.