Microbial Engraftment Kinetics After Microbiota Transplant Therapy in Ulcerative Colitis

Overview

Microbiota transplant therapy (MTT) using encapsulated donor microbiota results in significantly higher donor microbial engraftment in patients with mild-to-moderate ulcerative colitis compared to placebo. Engraftment kinetics differ from those observed in recurrent Clostridioides difficile infection, with baseline patient microbiome diversity inversely correlating with engraftment success.

Background

Ulcerative colitis (UC) is an inflammatory bowel disease characterized by dysbiosis of the gut microbiota. Microbiota transplant therapy (MTT) aims to restore a healthy microbial community by introducing donor microbiota, a strategy derived from fecal microbiota transplantation effective in recurrent Clostridioides difficile infection. Unlike rCDI, UC patients have a largely intact indigenous microbiota, making donor engraftment more challenging and less well understood. Understanding engraftment kinetics and donor taxa contributions is critical to optimizing MTT protocols for UC.

Data Highlights

Key Findings

• SourceTracker is an effective and reliable tool to quantify donor microbial engraftment and identify engrafting taxa in UC patients undergoing MTT.
• Patients receiving encapsulated MTT capsules showed significantly higher donor microbiota engraftment at week 12 compared to placebo.
• Baseline microbial diversity indices (Shannon and Chao1) negatively correlated with donor engraftment in treated patients, indicating that lower indigenous diversity may facilitate engraftment.
• Engraftment kinetics in UC differ from those observed in rCDI, with slower and more punctuated colonization patterns.
• Donor taxa from the phyla Firmicutes and Bacteroidetes were among those identified as engrafting in UC patients.

Clinical Implications

These findings suggest that encapsulated MTT can achieve meaningful donor microbiota engraftment in UC patients, which may contribute to therapeutic benefit. Baseline microbiome diversity could serve as a biomarker to predict engraftment success and guide patient selection. The distinct engraftment kinetics in UC highlight the need for tailored dosing strategies and donor selection to optimize clinical outcomes.

Conclusion

Encapsulated microbiota transplant therapy leads to significant donor microbial engraftment in ulcerative colitis patients, with engraftment patterns distinct from other indications. SourceTracker provides a valuable method to monitor engraftment and inform future therapeutic strategies.

References

1. Original Article 2024 -- Emerging Patterns of Microbial Engraftment After Microbiota Transplant Therapy in Patients with Ulcerative Colitis