Antimicrobial and immune modulatory effects of vaginal microbiota metabolites

HIV disproportionately affects adolescent girls and young women in sub-Saharan Africa, but those with an optimal vaginal microbiome are less susceptible. A nonoptimal vaginal microbiome is characterised by increased vaginal pH and different concentrations of microbiota metabolites.

Women colonised with optimal cervicovaginal microbiota, typically dominated by Lactobacillus species, are protected against HIV in contrast to women with a non-optimal vaginal microbiome (i.e. those with bacterial vaginosis).

Women with bacterial vaginosis experience a dramatic increase in vaginal pH and changes in the concentrations of vaginal microbiota metabolites including lactic acid, short chain fatty acids (SCFAs) and succinic acid. 

We aim to determine the role of these metabolites in inactivating HIV and other sexually transmitted infections (STIs), and their effects on cells of the female reproductive tract.

Objective

This study aims to determine the antiviral and immune modulatory effects of organic acid metabolites (including lactic acid, short chain fatty acids and succinic acid) to understand their role in either helping to protect against or to promote acquisition of HIV and STIs.

Approach

Physiological concentrations of microbiota metabolites will be assessed for ability to inactivate HIV and other STIs as well as to decrease or promote the production of pro-inflammatory cytokines in cervicovaginal cell culture models.

Community impact

Understanding the antimicrobial and immune modulatory effects of vaginal microbiota metabolites may lead to new strategies to optimize the vaginal microbiome and environment to prevent HIV and other STIs.