Calcium2026-07

Impact of microbiome alterations on fracture healing and nonunion: a narrative review.

Barbaroux Tomas Antoni, Khattak Asad Rehman, Husain Thamer Rahma Ali Salman Husain, Alqanaie Modhawi et al. — European journal of orthopaedic surgery & traumatology : orthopedie traumatologie

Summary

このレビューは、私たちの腸内に生息する細菌（腸内細菌叢）が、骨折後の骨の治癒にどのように影響するかを探っています。健康な腸内環境は、カルシウムなどの栄養素の吸収を改善し、炎症を抑えることで、より強い骨と効果的な修復をサポートすると考えられます。逆に、腸内細菌のバランスが崩れると、骨の回復が妨げられる可能性があります。

AI-generated summary — read the original

Key points

腸内細菌は、骨折がどれだけうまく治るかに重要な役割を果たします。
健康な腸内細菌のバランスは、骨を強くし、より良い骨折治癒をサポートします。
腸内細菌の乱れは、骨の修復を遅らせたり妨げたりする可能性があります。
将来的に、腸内細菌を標的とした治療が骨折治癒の改善に役立つかもしれません。

What the study looked at

This review investigated how the collection of bacteria living in our gut, called the microbiome, might affect the healing process of bone fractures and prevent complications where bones fail to mend properly. Researchers conducted a narrative review, which means they gathered and summarized findings from various existing experimental and clinical studies. They searched scientific databases for relevant papers published between 2013 and 2026 to synthesize current knowledge on the topic. The review found that the gut microbiome plays a crucial role in bone repair. A balanced microbiome can produce beneficial compounds that help build new bone cells, reduce the breakdown of existing bone, and improve the body's absorption of essential minerals like calcium. However, an unhealthy gut microbiome can lead to inflammation and a compromised gut barrier, which may slow down or impair fracture healing. The study also noted that a fracture itself could alter the gut bacteria, suggesting a two-way interaction. Future treatments targeting the gut microbiome, such as probiotics, show promise for improving bone healing, though more human studies are needed.

Dietary takeaway

While this is a review of existing studies and not a new experiment, it highlights that maintaining a healthy gut microbiome could indirectly support bone health and the efficient absorption of calcium, which is vital for strong bones. Eating a balanced diet rich in fiber and diverse whole foods can foster a healthy gut, potentially aiding your body's ability to utilize calcium and recover from bone injuries. Remember, findings from a single review are not definitive, and more research is always ongoing.

Abstract

INTRODUCTION: Fracture healing is a complex biological process determined by mechanical stability, vascular supply, and systemic physiological factors. Despite advances in fracture management, nonunion remains an important clinical challenge. Emerging evidence indicates that the gut microbiome is a key regulator of bone metabolism and fracture repair through immune modulation, nutrient digestion, and microbial signaling pathways. METHODS: We conducted a narrative review synthesizing experimental and clinical evidence on the impact of gut microbiome alterations on fracture healing and nonunion. Literature searches were performed in PubMed, Google Scholar, and Scopus for studies published between 2013 and 2026. A total of 107 records were initially screened by title and abstract, and 11 studies meeting inclusion criteria were included in the final synthesis. Many screened articles focused on osteoporosis, general bone metabolism or outcomes related to microbiome that didn't evaluate fracture healing, non-union, delayed union, or complications related to fractures, therefore they were excluded. RESULTS: The gut microbiome emerges as an important regulator of bone metabolism and fracture repair. Microbial metabolites, particularly short-chain fatty acids, are associated with enhanced osteoblast activity, suppressed osteoclast-mediated bone resorption, and improved calcium absorption, collectively supporting bone mineral density and trabecular integrity. Dysbiosis impairs fracture healing by promoting gut barrier dysfunction, increasing intestinal permeability, and elevating systemic inflammation. Elevated pro-inflammatory cytokines, including IL-17a, are linked to reduced callus mineralization and delayed bone regeneration. Evidence also suggests a reciprocal interaction, where fracture events can alter gut microbiome composition and function. Microbiome-targeted interventions, such as probiotic and prebiotic supplementation, show therapeutic potential by improving bone microarchitecture, stimulating osteogenic signaling, and mitigating inflammation. Clinically, microbial dysregulation, particularly in infection-associated states, correlates with prolonged healing times and increased bone loss. CONCLUSIONS: The gut microbiome is an emerging systemic regulator of bone metabolism and may influence fracture healing and nonunion risk through mechanisms that include immune modulation, microbial metabolites, and nutrient metabolism. Dysbiosis may impair bone regeneration and increase the risk of delayed union or nonunion. Microbiome-targeted therapies are promising, but more human studies are needed to confirm their clinical relevance. These findings highlight the interconnected roles of the microbiome, immune function, and metabolism in bone healing, underscoring the need for further research.

View on PubMed →DOI: 10.1007/s00590-026-04886-9