Microbiome-induced Increases and Decreases in Bone Tissue Strength can be Initiated After Skeletal Maturity

Area of Science:

• Microbiology
• Bone Biology
• Skeletal Physiology

Background:

• Emerging research links the gut microbiome to bone tissue strength in growing animals.
• It remains unclear if modulating the gut microbiome later in life affects bone matrix strength.

Approach:

• Antibiotics (ampicillin + neomycin) were used to alter gut microbiome composition in mice at different life stages (pre- and post-skeletal maturity).
• Five groups were studied: Unaltered, Continuous, Delayed, Initial, and Reconstituted microbiome groups.
• Bone matrix strength was assessed in 24-week-old male and female mice.

Key Points:

• In male mice, altering the gut microbiome before or after skeletal maturity significantly reduced bone matrix strength.
• Restoring the gut microbiota via fecal transplant normalized bone matrix strength in males.
• Female mice showed a similar trend, but the differences were not statistically significant, indicating sex-specific responses.

Conclusions:

• Gut microbiome modifications can impair bone matrix strength in adult male mice, with effects initiated or reversed post-skeletal maturity.
• These findings suggest microbiome-induced bone changes may occur independently of typical bone remodeling processes (osteoblast/osteoclast activity).
• The mechanical properties of the adult skeleton are sensitive to gut microbiome composition.