When you take antibiotics for a long time, like several days or weeks, a common side effect is a vaginal yeast infection or bacterial vaginosis (BV). The reason is that antibiotics can kill your normally protective bacteria in the gut and vagina, which might lead to yeast or BV.
You should avoid using antibiotics unless it is necessary. When you must use antibiotics, you should limit the dosage and duration. While you take antibiotics, we suggest that you take probiotics at the same time as a preventive measure (not simultaneously, but intermittently). For example, if you take antibiotics in the morning and afternoon, you may take probiotics in the evening and at night. The probiotics include yogurt that contains Lactobacillus cultures and probiotic pills like the NeuEve Vaginal Probiotic for Women.
Probiotic foods or pills are not antifungal drugs. They cannot kill yeast directly, and they are also sensitive to the antibiotics that you take. In fact, most ingested probiotics in the yogurt or pill will be killed soon after you take another dose of antibiotics. How could these probiotic Lactobacillus cells protect you against a possible yeast infection if they are soon dead?
One of the most common protection mechanisms is called "competitive exclusion."
Let me use a competition for parking spaces as an example.
In the human gut, each indigenous bacterium has its own parking spot. When you take antibiotics in the morning, millions of indigenous bacteria in the gut will be killed, leaving their parking spots open. But when you take probiotics in the afternoon, they will fill in these vacant spots as temporary placeholders. By continuously replenishing probiotics, the good bacteria will occupy these parking spots as a placeholder. Bad bacteria or yeast will not be able to find a parking place and will not cause an infection.
Once the antibiotic treatment stops, good bacteria in the gut will grow back and replace the probiotic bacteria to reoccupy their original parking spots. Food probiotics do not colonize in humans, at least not for the long term. However, even short-term colonization as a placeholder can help you prevent yeast or bacterial infection associated with antibiotic usage.
If you do not take probiotics, these parking spots will be open. Antibiotic-resistant bad bacteria or yeast may come in and take those spots to cause infection. This event often starts in the gut if you take antibiotics orally. Later, yeast and/or bad bacteria may get into the vagina via the fecal-urogenital passage to cause vaginal infection.
Therefore, taking probiotic foods and/or pills regularly during and a few days after antibiotic treatment will help you prevent yeast or drug-resistant bacteria infections both in the gut and vagina.