Effect of perioperative multistrain probiotics on the CT callus volume fraction at 12 weeks after surgery for closed tibial shaft fracture: a single-center randomized controlled study.
Huang Y, Zheng X, et al. • Frontiers in cellular and infection microbiology • 2026
Perioperative multistrain probiotics (Lactobacillus rhamnosus GG plus Bifidobacterium longum) significantly enhanced CT-based bone mineralization at 12 weeks after closed tibial shaft fracture surgery, with exploratory secondary findings suggesting earlier functional recovery and improved radiographic healing.
Key Findings
Results
Perioperative multistrain probiotics significantly increased CT-derived bone volume fraction (BV/TV) at 12 weeks compared to placebo.
The adjusted difference in BV/TV between the probiotics and placebo groups was Δ = 0.11 (95% CI 0.03–0.19; P = 0.012).
BV/TV was analyzed using ANCOVA adjusted for age, sex, AO/OTA fracture classification, smoking status, and postoperative interfragmentary gap.
BV/TV via CT was used as the primary outcome because conventional radiographs lack sensitivity for early healing, whereas CT-derived BV/TV allows quantitative assessment of callus mineralization.
CT segmentation showed excellent reliability with an intraclass correlation coefficient (ICC) of 0.96.
Results
Time to uncomplicated full weight bearing was shorter in the probiotics group compared to placebo.
Full weight bearing was defined as ambulation without assistive devices and without pain in the affected limb.
The difference was statistically significant (P = 0.041) by Kaplan-Meier analysis with the log-rank test.
This was an exploratory secondary outcome; nominal P values are reported without multiplicity adjustment.
The authors note these secondary findings warrant cautious interpretation due to the lack of multiplicity correction.
Results
Rest-pain VAS scores were lower in the probiotics group at postoperative week 2 but not at week 6.
The difference in VAS pain scores at week 2 was Δ = −0.55 (P = 0.047).
No statistically significant difference in VAS scores was observed at postoperative week 6.
This was an exploratory secondary outcome reported without multiplicity adjustment.
Results
Radiographic Union Score for Tibial Fractures (RUST) at 12 weeks was higher in the probiotics group.
The difference in RUST scores at 12 weeks was Δ = 0.68 (P = 0.019).
RUST is a validated radiographic scoring tool for assessing fracture healing.
This was an exploratory secondary outcome reported without multiplicity adjustment.
Results
No significant differences in adverse events or surgical site infection rates were observed between the probiotics and placebo groups.
Safety outcomes were analyzed using Fisher's exact test.
No significant between-group differences in adverse events were found.
No significant between-group differences in surgical site infection were found.
Methods
The trial enrolled 84 patients with closed tibial shaft fractures in a single-center, randomized, double-blind, placebo-controlled design.
The modified intention-to-treat population included participants who received at least one dose and completed follow-up.
Probiotics (Lactobacillus rhamnosus GG plus Bifidobacterium longum) or placebo were administered from the preoperative period through postoperative week 6.
The primary outcome was assessed at 12 weeks postoperatively.
The rationale for probiotics use was that perioperative antibiotics and surgical stress disrupt gut microbiota, potentially impairing fracture healing via immunomodulation and the gut-bone axis.
What This Means
This research suggests that taking a combination of two probiotic strains (Lactobacillus rhamnosus GG and Bifidobacterium longum) around the time of surgery for a broken shinbone may help the bone heal better. In this study of 84 patients, those who took probiotics from before surgery through six weeks after surgery had significantly more bone mineral content in the healing callus (the new bone tissue that forms at the fracture site) at 12 weeks, as measured by CT scan. The probiotics group also appeared to recover the ability to walk without assistance sooner, had less pain in the first two weeks after surgery, and showed better scores on a standard X-ray healing scale — though these additional findings were exploratory and should be interpreted with caution.
The reasoning behind testing probiotics for bone healing is that surgery and the antibiotics given around the time of the operation can disrupt the normal balance of bacteria in the gut. Scientists believe the gut microbiome influences bone health through pathways involving the immune system and what is sometimes called the 'gut-bone axis.' By restoring healthy gut bacteria with probiotics, the researchers theorized that the body's bone-repair processes might work more effectively. Importantly, the probiotics appeared to be safe — there were no differences in side effects or wound infections between the probiotic and placebo groups.
This research suggests that probiotics could one day become a simple, low-risk add-on to standard care for people recovering from fractures, potentially speeding up healing and reducing pain. However, because this was a single-center study with a relatively small number of patients and some of the promising results were exploratory, larger trials are needed before any firm conclusions can be drawn about whether probiotics should be routinely recommended after fracture surgery.
Check Your Own Numbers
Upload your bloodwork. We'll cross-reference your results against this study and 4,700 others.
Huang Y, Zheng X, Liao C, Liu G, Li M. (2026). Effect of perioperative multistrain probiotics on the CT callus volume fraction at 12 weeks after surgery for closed tibial shaft fracture: a single-center randomized controlled study.. Frontiers in cellular and infection microbiology. https://doi.org/10.3389/fcimb.2026.1778557