Threshold for post-FMT temporal stability prior to re-personalization

Determine a quantitative duration threshold for which the similarity of a recipient’s microbiome to the donated microbiome remains stable following fecal microbiota transplantation before the recipient microbiome re-personalizes, thereby operationalizing temporal stability after engraftment.

Background

The paper frames temporal stability as a core criterion for assessing engraftment success after fecal microbiota transplantation (FMT), noting that stability of the donated microbiome is typically observed for weeks to months after successful intervention before the microbiome often re-personalizes.

Despite this general understanding, the authors explicitly state that there is not yet an identified threshold for how long donor-like stability persists before re-personalization begins. Establishing such a threshold would help standardize assessments of engraftment success across studies and clarify expected temporal dynamics.