Association between dietary patterns and bacterial vaginosis: a case–control study

Bacterial vaginosis (BV) is a predominant vaginal disturbance that affects about 25% of childbearing-aged women. Dietary consumption may have a crucial role in vaginal flora imbalances. This study was a hospital-based case–control study. In total, 144 incident BV cases and 151 healthy participants were recruited from the gynecology clinic in Tehran, Iran, between November 2020 and June 2021. Participants' typical diets were collected by a food frequency questionnaire. Vaginal flora was characterized based on the Amsel criteria. Factor analysis was used to pinpoint the principal dietary patterns. For logistic regression, the first tertile was assumed as a reference. Five principal dietary patterns emerged and were nominated as "Healthy diet," "Unhealthy diet," "Ovo-vegetarian diet," "Pseudo-Mediterranean diet," and "Western diet." The "Unhealthy diet" pattern were positively associated with BV (adjusted odds ratio (aOR) = 3.35; 95% confidence interval (CI) 1.41, 7.94; p(trend): 0.006), while adherence to the "Ovo-vegetarian diet" pattern was associated with a reduced odds of BV (aOR = 0.16; 95% CI 0.07, 0.34; p(trend) < 0.001). These results provide evidence that following the "unhealthy diet" pattern may lead to developing BV, and plant-based eating patterns may be associated with reduced BV odds.