The vaginal biofilm, a thin, sticky layer of bacteria on the vaginal lining, is an essential, yet often overlooked, component of female health. This microscopic community of bacteria can influence vaginal odor, discharge, and the occurrence of infections, according to OB-GYN Dr. Kate McLean.
This biofilm acts as a protective shield. When beneficial bacteria, such as lactobacilli, form the biofilm, they prevent harmful bacteria from colonizing the vagina. However, problematic biofilms can develop when certain bacteria, like Gardnerella vaginalis or Prevotella spp., create a protective layer that can lead to conditions such as bacterial vaginosis (BV) and yeast infections. These harmful biofilms can make infections more difficult to treat, sometimes leading to recurring symptoms even after medical intervention.
Biofilms are a natural occurrence not exclusive to the vagina; they can be found on teeth, in the gut, and on the skin. While societal emphasis on cleanliness can lead some to believe that vaginas should be odorless, a healthy vagina naturally has a scent and produces discharge, both of which are normal functions. Overly aggressive cleaning practices, such as douching, can disrupt the delicate balance by killing beneficial bacteria.
Recurring vaginal symptoms are often driven by complex biological factors, including the vaginal microbiome, rather than poor hygiene, McLean explained. The balance of bacteria is key to vaginal health.
Lactobacilli, a beneficial bacteria, are crucial for maintaining a healthy vaginal environment. They produce lactic acid, which lowers the vagina's pH, and also generate hydrogen peroxide and bacteriocins. These actions collectively make the environment inhospitable to undesirable bacteria. The biofilm created by lactobacilli serves as a physical barrier, blocking colonization by harmful bacteria.
Disruptions to this balance can occur due to factors like antibiotic use, douching, or unprotected sex, which can reduce lactobacilli populations and allow other bacteria to flourish. When this happens, anaerobic bacteria can form biofilms that cause infections like BV, characterized by symptoms such as grey or white discharge, a fishy odor, and itching or burning.
The protective nature of biofilms can make bacteria up to 1,000 times more tolerant to antibiotics or antifungals. Treatments may clear the surface of the biofilm but fail to eradicate the problem entirely. Bacteria use biofilms as a survival strategy, resisting environmental changes and immune responses. This dormancy allows bacteria to regrow once the perceived threat has passed. It is estimated that as many as 60% of women with BV experience a repeat infection within a year of treatment.
McLean advises seeking medical attention for persistent vaginal symptoms to identify the underlying cause. Treatment for BV, for instance, typically involves oral or vaginal antibiotics. Long-term vaginal health management includes supporting a healthy vaginal microbiome, avoiding unnecessary disruptions, and seeking appropriate care when symptoms arise.