The role of Bacillus acidophilus in osteoporosis and its roles in proliferation and differentiation

BACKGROUND Osteoporosis is one of the most closely related diseases associated with the elderly. In recent years, the studies found that gut microbiota can cause osteoporosis. We evaluated the role of Bacillus acidophilus in osteoporosis and its roles in proliferation and differentiation. METHODS We selected 5 healthy people and 10 osteoporosis patients and analyzed their level of 25-hydroxyvitamin D and procollagen type I N-terminal peptide (PINP), the characteristic of gut microbiota. The effect of lactobacillus acidophilus and Lactobacillus rhamnosus supernatant and butanoic acids on proliferation, differentiation, and maturity of osteoblasts MC3T3-E1 and osteoclasts RAW 264.7 cells and the activity of alkaline phosphatase, concentration of osteocalcin, and the expression of RUNX2, RANK, NFATc1, cathepsin K, DC-STAMP, OSCAR, WNT2, and CTNNB1 were measured in the above cell lines. RESULTS The diversity of gut microbiota in osteoporosis patients is decreased and imbalanced with lower abundance of lactobacillus and butyric acid bacteria; meanwhile, 25-hydroxyvitamin D and PINP of osteoporosis patient were significantly lower than the normal group. The proliferation, differentiation, and maturity of MC3T3-E1 cells were stimulated; the activity of alkaline phosphatase, concentration of osteocalcin, and the expression of RUNX2, NFATc1, cathepsin K, DC-STAMP, OSCAR, WNT2, and CTNNB1 were improved by supernatant of lactobacillus acidophilus, Lactobacillus rhamnosus and butanoic acids; however, the proliferation, differentiation, maturity, and the expression of RANK, NFATc1, cathepsin K, DC-STAMP, OSCAR, WNT2, and CTNNB1 in RAW 264.7 cells were suppressed. CONCLUSIONS The lactobacillus acidophilus and Lactobacillus rhamnosus supernatant could stimulate the proliferation, differentiation, and maturation of osteoblasts; the production of butyric acid may be the potential mechanism.