Abstract
To investigate the effects of lifetime duration of oral contraceptive (OC) use, we reanalyzed publicly available 16S rRNA sequencing data from fecal samples of OC users and non-users collected at different timepoints in the menstrual cycle. We profiled the microbial composition of subjects and identified 32 significantly differentially abundant Amplicon Sequence Variants (padj<0.05) with increasing lifetime use duration including 16 ASVs belonging to class Clostidia that decreased with longer OC use. Some Clostridia species are known to recycle estrogen; lifetime duration of OC exposure could thus influence women's health through gut microbiome composition and hormone regulation.