Probiotics ameliorate alveolar bone loss by regulating gut microbiota

Objectives Oestrogen deficiency is an aetiological factor of postmenopausal osteoporosis (PMO), which not only decreases bone density in vertebrae and long bone but also aggravates inflammatory alveolar bone loss. Recent evidence has suggested the critical role of gut microbiota in osteoimmunology and its influence on bone metabolisms. The present study aimed to evaluate the therapeutic effects of probiotics on alveolar bone loss under oestrogen-deficient condition. Materials and Methods Inflammatory alveolar bone loss was established in ovariectomized (OVX) rats, and rats were daily intragastrically administered with probiotics until sacrifice. Gut microbiota composition, intestinal permeability, systemic immune status and alveolar bone loss were assessed to reveal the underlying correlation between gut microbiota and bone metabolisms. Results We found administration of probiotics significantly prevented inflammatory alveolar bone resorption in OVX rats. By enriching butyrate-producing genera and enhancing gut butyrate production, probiotics improved intestinal barrier and decreased gut permeability in the OVX rats. Furthermore, the oestrogen 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. Conclusions This study demonstrated that probiotics can effectively attenuate alveolar bone loss by modulating gut microbiota and further regulating osteoimmune response and thus represent a promising adjuvant in the treatment of alveolar bone loss under oestrogen deficiency.

Automated summary

This study found that probiotics effectively prevented inflammatory alveolar bone resorption in OVX rats by enriching butyrate-producing genera and improving gut barrier function. Probiotics also suppressed estrogen deprivation-induced inflammatory responses, as evidenced by reduced levels of inflammatory cytokines and balanced distribution of immune cells in bone marrow. These findings suggest that probiotics can serve as a promising adjuvant in the treatment of alveolar bone loss under estrogen deficiency.