Migration and standing variation in vaginal and rectal yeast populations in recurrent vulvovaginal candidiasis

Vaginal yeast infections are very common, yet we do not understand why some people experience chronic infections when most have a single infection that is successfully treated and cleared. We examined 12 vaginal and 12 rectal yeast isolates from four individuals with a history of recurrent yeast infections (total 96 isolates). Three participants had a <i>Candida albicans</i> infection (the most common causative species), while the fourth had a <i>Nakaseomyces glabratus</i> infection (the second most common and increasingly implicated). We found that vaginal and rectal isolates were closely related genetically, indicating the same population is present at the two sites. Surprisingly, we found that diversity was similar to the yeast populations found at other body sites in healthy people. Our study highlights a critical need for additional studies following the same methods in different contexts to better understand the fungal microbial populations in our bodies.