Sex Differences in Fecal Microbiota Transplantation for Mitigating Radiation-Induced Thrombocytopenia in Mice: Efficacy Amplified by Inulin

BACKGROUND:Fecal microbiota transplantation (FMT) shows potential in promoting hematopoiesis, with efficacy influenced by donor sex. However, its role in radiation-induced thrombocytopenia (RIT) and its sex-specific effects remain unclear. While inulin may enhance FMT efficacy, this has not been explored in the context of RIT. METHODS:We established an irradiation-induced thrombocytopenia (RIT) model in male and female mice via 4 Gy X-rays exposure. FMT was administered orally as a fecal suspension. Platelet recovery was monitored via hematology analyzer, megakaryopoiesis was assessed by flow cytometry and H&E staining; gut microbiota changes were evaluated by 16S rRNA sequencing. RESULTS:Sex-matched FMT accelerated platelet recovery and promoted megakaryocyte production in the bone marrow and spleen only in female mice, accompanied by an increase in Akkermansia abundance. Furthermore, transplanting feces from female donors also accelerated platelet recovery in irradiated male mice, whereas feces from male donors does not. INU selectively enriched probiotic colonization, thereby fostering a favorable microbial structure that enhanced FMT efficacy. CONCLUSIONS:The sexually dimorphic gut microbiota contributes to sex-specific FMT efficacy in alleviating radiation-induced thrombocytopenia, which can be further amplified by inulin. This study offers sex-specific microbial therapy for radiation-induced thrombocytopenia and a prebiotic-based strategy to boost FMT efficacy.