Yeast Infection After Antibiotics: Do Probiotics Prevent It?

Antibiotics clear the infection you took them for, and sometimes leave you with an itch. Thrush (a vaginal yeast infection) can develop when antibiotics change the balance of bacteria.¹

How common it is

In a trial run through family practices and pharmacies in Melbourne, Australia, 235 women aged 18 to 50 taking a short course of antibiotics for an infection elsewhere in the body were followed.² 23% developed vulvovaginitis afterward.²

Did probiotics prevent it?

The same trial tested lactobacillus, the “good bacteria” sold for vaginal health, taken by mouth, vaginally, or both, from the start of the antibiotics until four days after.²

• Neither form reduced post-antibiotic vulvovaginitis compared with placebo.²
• The trial was stopped early because the probiotics weren’t working.²
• The authors concluded the results don’t support lactobacillus for prevention.²

It was a well-designed, double-blind, placebo-controlled trial.² It tested particular products, so it can’t rule out every probiotic, but it’s the strongest direct test we found. See vaginal probiotics.

Is it yeast?

Typical thrush: white, cottage-cheese discharge that doesn’t usually smell, itching around the vulva, and soreness or stinging with sex or peeing.¹ A fishy smell points more toward bacterial vaginosis, and stinging mainly when peeing could be a urinary infection. See yeast, BV or UTI: how to tell.

What to do

1. A pharmacy antifungal usually clears thrush within 7 to 14 days of starting treatment.¹ See over-the-counter yeast treatments.
2. Wash with water and a plain emollient, and skip soaps, shower gels and douches.¹
3. See a clinician if it’s your first episode, you’re over 60, it’s come back more than 4 times in a year, or treatment hasn’t worked.¹ Don’t use antifungals more than twice in 6 months without advice.¹
4. Tell the prescriber if antibiotics reliably give you thrush, so it can be planned for next time.

HRT is also on the list of things that can trigger thrush.¹ For repeat episodes, see why you keep getting yeast infections.

Try: “Every time I take antibiotics I get thrush within a week. Can we plan for that next time, and is it worth checking whether it’s yeast at all?”

Down There, Decoded covers repeat infections in Chapter 7, “Here We Go Again,” in a section called “When Yeast Comes Back.” Its Down-There Log records each episode with dates and any antibiotics in the weeks before, so a pattern is easy to show. See the book.