The following is a summary of “Condomless vaginal intercourse and lubricant use are independently associated with antioxidants within the vaginal tract,” published in the FEBRUARY 2023 issue of Obstetrics and Gynecology by Borgogna J et al.

For a study, researchers sought to investigate whether vaginal intercourse and lubricant use affected the vaginal metabolome, which provided broad-spectrum protection against urogenital infections through the action of key immunomodulatory metabolites such as lactic acid.

The study utilized untargeted metabolomics combined with 16S rRNA sequencing to evaluate the impact of condomless penile-vaginal intercourse, with and without lubricant use, on the vaginal microenvironment. Mid-vaginal swabs were collected from a 10-week observational cohort of reproductive-age participants who recorded daily behavioral diaries. A nested case-control analysis assessed metabolomic differences in vaginal samples obtained the day before and after condomless intercourse with lubricants (22 cases) and without lubricants (22 controls). Cases were matched on race/ethnicity to controls. Bayesian mixed-effects regression of log2-transformed metabolites was used to analyze the data.

Time-varying factors, such as menses, did not significantly affect the metabolome. The study found that condomless penile-vaginal intercourse was significantly associated with up to 4-fold increases in oxidative-stress metabolites and host-produced antioxidants, regardless of the vaginal microbiota and lubricant use. Lubricant use was significantly associated with up to 8.3-fold increases in host-produced antimicrobial sphingolipids, antioxidants, osmoprotectants, and salicylate, a cooling agent common to lubricants, after controlling for condomless penile-vaginal intercourse and microbiota. The oxidative stress and salicylate metabolites were strongly correlated with several BV-associated bacteria.

The study concluded that lubricant use and condomless penile-vaginal intercourse might independently affect the protective mechanisms in the vaginal metabolome. Both may elicit oxidative-stress-related metabolites from host epithelial cells, enabling BV-associated bacteria to evade host defenses and persist.

Source: ajog.org/article/S0002-9378(22)01005-5/fulltext