Probiotics Ameliorate Alveolar Bone Loss by Regulating Gut Microbiota

Abstract BackgroundEstrogen deficiency is an etiological factor of postmenopausal osteoporosis (PMO), which not only decreases bone density in vertebrae and long bone, but also aggravates inflammatory bone loss in alveolar bone. Recent evidence has suggested the critical role of gut microbiota in osteoimmunology, and modulation of gut microbiota may have positive influence on bone metabolisms. The present study aimed to evaluate the therapeutic effects of probiotics on alveolar bone loss under estrogen-deficient condition. Inflammatory alveolar bone loss induced by either chronic periodontitis or apical periodontitis was established in ovariectomized (OVX) rats, which were gavage-fed with probiotics daily until sacrifice. Gut microbiota and gut permeability, as well as alveolar bone loss and the related osteoimmune were evaluated to investigate the effects and underlying mechanisms by which probiotics counter the alveolar bone loss under estrogen-deficiency. ResultsWe found that administration of probiotics significantly prevented periodontal and apical bone resorption in OVX rats. Administration of probiotics significantly enriched butyrate-producing genera and enhanced gut butyrate production, resulting in improved intestinal barrier and decreased gut permeability in the OVX rats. Furthermore, the estrogen deprivation-induced inflammatory responses were suppressed in probiotics-treated OVX rats, as reflected by reduced serum levels of inflammatory cytokines and a balanced distribution of CD4+IL-17A+Th17 cells and CD4+CD25+Foxp3+Treg cells in the bone marrow. ConclusionOur data demonstrate that probiotics can effectively attenuate alveolar bone loss by modulating gut microbiota and further regulating osteoimmune, and thus represent a promising adjuvant in the treatment of alveolar bone loss under estrogen-deficiency.