METAGENOMIC ANALYSIS OF HUMAN FECAL VIROME SHOWED GEOGRAPHY AND POPULATION-SPECIFIC SIGNATURES IN OBESITY

Background: Fecal microbiota transplantation (FMT) is a safe, effective intervention for patients with recurrent or severe Clostridioides difficile infection (CDI).Mounting evidence suggests that the colonic epithelium and microbiome are altered by estrogen and other sex hormones.However the effect of patient sex on FMT efficacy for CDI has not been studied.Methods: This is a retrospective cohort study of patients who underwent FMT between 2014 and 2016 for recurrent or severe CDI at one academic center.The primary outcomes were CDI recurrence at 6 months after FMT and colectomy.Patient characteristics, risk factors and outcomes were compared using chi-squared tests with a significance threshold of p <0.05.Results: The cohort included 134 patients, 86 female (64%), who underwent FMT during this time period.The average age was 56.3 for females and 46.8 for males.The study included 45 IBD patients (24 female).Differences in IBD severity and immunosuppressive medication use were not significant by sex among the IBD subgroup.The average number of previous CDI was 3.6 for females and 3.2 for males.Most were performed as outpatient (78%).The frequency of severe CDI (19%) and presence of pseudomembranes (38%) was the same for both sexes.17 females (20%) and 11 males (23%) had relapse of CDI by 6 months.7 female and 1 male patient required colectomy for FMT failure (p= 0.17).When further stratified by IBD status and patient sex, outcomes were not significantly different.Conclusion: Although females comprise the majority of patients in FMT studies for CDI, this study does not demonstrate any significant differences in characteristics, risk factors, severity of CDI, or FMT failure by patient sex.However, there was a trend towards increased colectomy among females (p=0.17).Despite emerging evidence that sex hormones alter the microbiome, this does not appear to impact clinical efficacy of FMT.Other factors that may change hormone levels, such as age, use of hormone replacement therapy or donor sex for FMT, warrant further investigation.