Antibiotics play a critical role in killing bad bacteria. But as they destroy infections, they can cause collateral damage to the good bacteria in your gut, which could result in diarrhea for a couple of days—or even weeks—after you stop taking the medicine.
So how can you get the benefits of antibiotics without the nasty stomach side effects? The answer might be found in probiotics—capsules with live microorganisms that offer health benefits.
Your intestines contain around 1,000 different species of bacteria, with 100 trillion bacteria in total, said Dr. Lawrence Hoberman, president and chief executive of Medical Care Innovations Inc. If 80% of that bacteria is the good, healthy kind, the harmful bacteria stays at bay. But antibiotics change the balance in the microbiome, which may result in an increase in the harmful bacteria, he explained.
“The immune system recognizes the bad guys and will try to destroy them. But in the process, it breaks down the intestinal lining and causes inflammation, and that’s how we get antibiotic-associated diarrhea,” Dr. Hoberman explained.
One study found that antibiotic-associated diarrhea affects between 5% and 39% of patients, depending on which antibiotic they take. But research shows that probiotics can curb digestion problems. A meta-analysis of 34 other studies found that probiotics reduce instances of antibiotic-associated diarrhea by 52%.
This is why doctors often suggest taking probiotics when you’ve been prescribed antibiotics—just be sure to space out when you take them.
“The antibiotic can kill the good bacteria in the probiotic,” Dr. Hoberman said. “By waiting two hours, the probiotic or antibiotic level is low in the intestines. It doesn’t make any difference which is taken first as long as it’s separated by two hours.”
He also added that it’s important to continue taking probiotics for at least a week after your course of antibiotics ends.
Which probiotics should you take with antibiotics?
Your pharmacy probably has shelves filled with different bottles of probiotics. How do you choose the right probiotics to take with your antibiotics? Dr. Bryan Tran, cofounder of DrFormulas, recommends looking for probiotics that have the “three Ds”:
Dose: The amount of active micro-organisms in a probiotic is measured in colony-forming units, or CFUs. “You want a dose with 10 billion CFUs or higher,” Dr. Tran said. And while you may see probiotics with 100 billion or more CFUs, according to Dr. Hoberman, you generally stop reaping added benefits after about 20 billion.
Diversity: The label on a bottle of probiotics will also tell you which bacteria strains the capsules contain. Look for probiotics that have five to 10 unique strains. “Studies that compare single-strain probiotics to multi-strain probiotics have found that a variety of strains is more effective at reducing diarrhea,” said Dr. Tran.
Delayed-release mechanism: Finally, look for probiotics that use delayed-release capsules. “When you take probiotics orally, you expose them to your stomach acid and that reduces the effective dosage that makes it to the gut,” said Tran. “Probiotics with delayed-release mechanisms won’t release the microorganisms until they go past the stomach.”