How long after taking antibiotics should you take probiotics

In short: Yes, you can take a probiotic while you’re taking an antibiotic—it’s perfectly safe to do so. In fact, experts generally agree that probiotics may help ward off the gut reaction that comes from taking antibiotics (such as diarrhea), but the data is limited. On the other hand, to reap the maximum gut flora-restoring benefits that probiotics offer, it may be better to wait until the tail-end of your course of antibiotics before starting to take them, says Eric Goldberg, M.D., an internist and medical director of NYU Langone Internal Medicine Associates in New York City.

To understand how probiotics and antibiotics work together, let’s first talk about the gut microbiome. The microbiome is where trillions of bacteria, fungi, and viruses live. We all have a balance of good and bad bacteria in our gut microbiome. When levels of the harmful bacteria get too high, you get sick—in the form of stomach “bugs,” fungal infections, and a hit to your immune system, making you more vulnerable to future infection.

How Do Antibiotics Work?

You likely know that antibiotics are medications that kill harmful bacteria that cause infections such as strep throat or a urinary tract infection. Broad-spectrum antibiotics, such as amoxicillin or tetracycline, target multiple strains of bacteria at once. Newer, narrow-spectrum antibiotics (such as erythromycin and clindamycin) zero in on a more limited range of organisms. The downside of both is that they can kill good bacteria, too, but the broad-spectrum antibiotics are the ones that carries the most significant risk. When good bacteria get wiped out, you may get an upset stomach with loose stool, a phenomenon known as antibiotic-associated diarrhea (AAD). In addition, women prone to yeast infections may experience one after a course of antibiotics as fungus can thrive in the genital area without enough good gut flora hanging around.

What Are Probiotics?

Probiotics, on the other hand, seek to pre-load your gut with living microorganisms that are known to fight inflammation, improve the immune response, and destroy disease-causing cells, according to the National Center for Complementary and Integrative Health. They are essentially the “good bacteria” in your gut that can take a hit when you are on antibiotics.

So, while considered safe, it may be counterproductive to take both probiotics and antibiotics simultaneously, says Dr. Goldberg. “The antibiotic is likely killing whatever the probiotic is adding,” he says. However, taking probiotics toward the end of your course of antibiotics (which usually runs about a week) ensures that the antibiotic has had some time to do its job correctly. As the antibiotics in your system wane, you can start to repopulate the beneficial bugs.

Not everyone is onboard with that theory, however: Alia Aaeedy, the director of pharmacy at Texas Surgical Hospital in Plano, Texas, says some research suggests antibiotics and probiotics can be taken in the same window of days as long as you separate your doses by two to three hours to avoid the cancel-out factor.

How to Take Probiotics

How long after you stop an antibiotic should you continue to take your probiotic? Experts say one to four weeks, but the research is unclear. A study published in the journal Cell found that participants who took a probiotic for four weeks after an antibiotic were able to restore their gut microbiome to normal after six months; the placebo group, however, colonized new, healthy gut bacteria in just three weeks. (Researchers say it’s possible that the particular blend of probiotics in the study wasn’t effective on that particular antibiotic and more research is needed to confirm the results.)

The upshot here? The benefits of taking a probiotic with or after an antibiotic isn’t 100% confirmed, but there is little downside to trying it. Stick to the more studied strains such as Lactobacillus, Bifidobacterium, and Saccharomyces. Look for supplements with USP seal, a dietary supplement certification that ensures the bottle contains what it says it does. The FDA does not regulate probiotics, so it’s essential to do some legwork. You can also eat your probiotics in active culture-containing and fermented foods and drinks such as yogurt, sauerkraut, miso, and kefir.

• General Info: National Central for Complementary and Integrated Health. (n.d.) “Probiotics: What You Need to Know.” https://www.nccih.nih.gov/health/probiotics-what-you-need-to-know

• Probiotic and AAD: The Journal of Family Practice. (2013.) “Prescribing an Antibiotic? Pair it with Probiotics.” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3601687/

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Krista Bennett DeMaio

Krista Bennett DeMaio has well over a decade of editorial experience. The former magazine-editor-turned-freelance writer regularly covers skincare, health, beauty, and lifestyle topics. Her work has appeared in national