The Effect of Lacticaseibacillus paracasei LPC100 and Lactiplantibacillus plantarum LP140 on Bone Mineral Density in Postmenopausal Women: A Multicenter, Randomized, Placebo-Controlled Study

<b>Objectives:</b> modulation of gut microbiota by probiotics has been proposed as a target for intervention to reduce bone mineral density (BMD) loss in the postmenopausal period. This study aims to evaluate the effect of <i>Lacticaseibacillus</i> (L.) <i>paracasei</i> LPC100 and <i>Lactiplantibacillus</i> (L.) <i>plantarum</i> LP140 on BMD in postmenopausal women in a multicenter, randomized, double-blind, placebo-controlled trial. <b>Methods:</b> the primary outcome was the change in T-score of the lumbar spine measured by dual-energy X-ray absorptiometry assessed after twelve-month probiotic supplementation. Secondary outcomes included changes in serological markers of inflammation and calcium-phosphate metabolism, body mass index, gastrointestinal symptoms, and satisfaction with the intervention. <b>Results:</b> a decrease in T-score indicating the progressive bone demineralization reached a statistically significant difference in the placebo group (from mean values of 0.06 ± 1.04 to -0.28 ± 1.12, <i>p</i> = 0.041) but not in the probiotic group (0.19 ± 0.99 and -0.08 ± 1.05, respectively, <i>p</i> = 0.125) with a <i>p</i>-value = 0.089 between the groups. No significant differences were found in secondary outcomes with the exception of vitamin D concentration and a significant reduction in some gastrointestinal symptoms in the probiotic group. A significant decrease in vitamin D level was observed only in the placebo group (<i>p</i> = 0.014). Probiotics were safe and well tolerated. <b>Conclusions:</b> this study suggests that the oral administration of <i>L. paracasei</i> LPC100 and <i>L. plantarum</i> LP140 may be a viable strategy to prevent BMD loss and vitamin D deficiency in postmenopausal women, but further research is necessary to confirm clinical benefits and to know the mechanism of action [ClinicalTrial.gov NCT06375668].