Frozen and lyophilized preparations in fecal microbiota transplantation (FMT) are highly efficacious for treating Clostridium difficile infection (CDI), according to a study in the Journal of Clinical Gastroenterology.
Researchers conducted a systematic review and network meta-analysis to review the current data available and determine the most efficacious FMT modality.
Searching multiple databases, researchers identified eligible studies that included patients who were undergoing FMT transplantation after the failure of antibiotic therapy to treat CDI. Interventions were fresh, frozen, and lyophilized FMT, with a head-to-head comparison of 2 of 3 FMTs or all 3 FMTs. The outcome was a resolution of symptoms.
Researchers performed a meta-analysis to obtain direct evidence for studies making a direct comparison among the intervention groups and a network meta-analysis to generate direct and indirect evidence comparing the groups simultaneously.
A total of 8 studies with 616 patients were included. Each study evaluated fresh FMT, 6 assessed frozen FMT, and 3 studies evaluated lyophilized FMT. Fresh FMT was the most successful with 93% efficacy (95% CI, 0.913-0.999), followed by frozen with 88% efficacy (0.902; 95% CI, 0.857-0.947) and lyophilized with 83% efficacy (0.828; 95% CI, 0.745 to 0.910) based on a pooled proportion meta-analysis.
In the direct meta-analysis, no statistically significant difference was found between the fresh and frozen groups in 6 studies (risk difference [RD], -0.051; 95% CI, -0.116 to 0.014; P =.178) with I2=34.4% (0.0%; 75.1%). No significant differences were observed in the frozen vs lyophilized groups in 3 studies (RD, -0.061; 95% CI, -0.038 to 0.160; P =.617) with I2=0% (0.0%; 89.6%).
In the network meta-analysis, a lower recovery rate was observed in the frozen group (RD, -0.06; 95% CI, -0.11 to 0.00; P =.05) and the lyophilized group (RD, -0.16; 95% CI, -0.27 to 0.05; P =.01), compared with the fresh group. The heterogeneity in this model was 20.1% with CI (0.0%; 62.5%).
The fresh group was ranked highest (0.99), followed by the frozen group (0.50) and lyophilized group (0.02), according to the frequentist approach and P score.
Study limitations include the lack of standardization of FMT, as patients with recurrent or refractory CDIs were assessed. Also, further stratification of patients according to age, sex, donor status, and a previous or current history of inflammatory bowel disease is needed, and the review included studies with small sample sizes.
“The efficacy of frozen and lyophilized FMT is high, and a reduction in the relative overall efficacy trend, based on our network analysis, is very small,” the study authors noted. “Any minor reduction is outweighed by the safety, accessibility, and practicality of frozen or lyophilized preparations. Additional studies evaluating feasibility, accessibility, and cost analysis should be performed. There should also be a focus on continuous improvement in processing frozen and lyophilized FMT and potentially evaluating the role of using fresh FMT after frozen FMT failure.”