# A synbiotic medical food improves gut barrier function, reduces immune responses, and inhibits osteoclast activity in models of postmenopausal bone loss aligned with clinical outcomes

## TL;DR

A synbiotic food improves gut health and reduces bone loss in postmenopausal women by reducing inflammation and inhibiting bone-degrading cells.

## Contribution

This study identifies a synbiotic medical food that modulates the gut–bone axis to reduce postmenopausal bone loss in clinical and preclinical models.

## Key findings

- SBD111 improves intestinal barrier integrity and reduces immune cell cytokine secretion in vitro.
- SBD111 inhibits osteoclast activity and bone resorption in postmenopausal models.
- Clinical outcomes align with reduced gastrointestinal symptoms and bone loss markers.

## Abstract

Over half of women above age 50 are affected by osteopenia or osteoporosis, bone-loss conditions influenced by estrogen decline, inflammation, and the intestinal microbiota. Probiotic-based interventions have shown promise in preclinical osteoporosis models. In a recent randomized, double-blind, placebo-controlled clinical trial of postmenopausal women, dietary intervention with SBD111, a synbiotic medical food combining plant-derived microbes and prebiotic fibers, reduced bone loss in women with osteopenia, elevated body mass index (BMI), and/or elevated body fat.

To investigate potential mechanisms underlying these outcomes, we examined intestinal epithelial, immune, and osteoclast responses to SBD111 in vitro. SBD111 administration improved intestinal barrier integrity, reduced immune cell cytokine secretion, and inhibited osteoclast activity. These effects align with clinically observed reductions in severe gastrointestinal symptoms and bone resorption markers. Together, these findings suggest that SBD111 modulates the gut–bone axis via barrier, immune, and antiresorptive pathways, supporting its role in maintaining skeletal health in postmenopausal women.

SBD111 synbiotic medical food reduces bone loss via barrier improvement, anti-inflammation, and osteoclast inhibition. (A) SBD111 improves barrier integrity in vitro. Visualized in the left panel, inflammation (seen in red) reduces intestinal epithelial barrier function, resulting in the influx of inflammatory mediators, thereby activating the immune system. The addition of SBD111, shown in purple (right), improves barrier function, reducing the ability of inflammatory mediators to cross the epithelial barrier. (B) SBD111 reduces inflammatory responses of inflamed immune cells in a concentration-dependent manner. Low concentrations of SBD111 induce inflammatory responses. At higher concentrations, fewer inflammatory cytokines are secreted. (C) SBD111-derived components/metabolites inhibit the activity of bone-resorbing osteoclasts and reduce their ability to degrade bone. Image created in https://BioRender.com. Green, R. (2025) https://BioRender.com/agmo9s8.