Can you take probiotics alongside antibiotics?

• Probiotics taken alongside antibiotic therapy may help prevent antibiotic-associated diarrhea and support the restoration of beneficial gut bacteria.
• Space probiotic and antibiotic doses at least two hours apart to prevent reduced antibiotic efficacy.
• Select probiotic products that contain multiple bacterial strains and provide a substantial number of colony-forming units (CFUs).
• Eating prebiotic and probiotic-rich whole foods during antibiotic treatment offers additional support for maintaining a healthy gut microbiome.

While antibiotics are essential for fighting bacterial infections, they can damage the beneficial microbes that reside in your gut, sometimes leading to diarrhea that persists even after you finish your course. The side effects can be uncomfortable, but there may be a solution: probiotics are living microorganisms that support digestive health and may help offset some of the gastrointestinal complications that come with antibiotic use. This article explores what research shows about using probiotics alongside antibiotics and how to approach them safely.

How antibiotics affect gut health

Antibiotics are drugs designed to combat bacterial infections by either destroying bacteria outright or stopping them from multiplying. Depending on the infection's severity and location, these medications may be swallowed as oral tablets or capsules, applied directly to skin, or given by intravenous injection for serious systemic infections. Because they target bacteria specifically, antibiotics are ineffective against viruses. They should be used judiciously and only when prescribed, as unnecessary use contributes to antibiotic resistance—a phenomenon in which bacteria develop the ability to survive antibiotic exposure.

Why antibiotics can cause stomach upset

The human gastrointestinal tract hosts an enormous ecosystem of roughly 100 trillion microbes—bacteria, fungi, viruses, and parasites—collectively called the gut microbiome or gut flora. These microorganisms play crucial roles in digestion, nutrient production, metabolic regulation, immune function, and even mental health. Under normal circumstances, beneficial and harmful microbes coexist in equilibrium, with the good microbes supporting overall wellness.

When you take antibiotics, this delicate balance shifts. As board-certified gastroenterologist Lawrence Hoberman, MD, explains: "Antibiotic use changes the balance in the gut microbiome, which may result in a decrease in the healthy bacteria and an increase in the harmful bacteria." This disruption can reduce microbial diversity and alter how the remaining organisms function. The result may include nausea, diarrhea, and in some cases, overgrowth of harmful bacteria like Clostridioides difficile (C. difficile or C. diff). Research indicates that antibiotic-related diarrhea affects between 5% and 39% of patients, depending on which antibiotic they receive.

C. difficile becomes problematic when antibiotics eliminate the beneficial bacteria that normally keep it in check. A C. difficile infection can range from persistent diarrhea to severe, life-threatening inflammation of the colon. Doctors diagnose this condition using stool testing and typically treat it with oral antibiotics such as vancomycin or fidaxomicin.

Is it advisable to take probiotics with antibiotics?

Many people experience digestive upset during antibiotic treatment and seek relief. Probiotics may offer a solution. Multiple studies demonstrate that probiotics can reduce digestive complications when taken alongside antibiotics. A meta-analysis spanning 34 trials found that probiotics reduced instances of antibiotic-associated diarrhea by 52%. The mechanism is straightforward: probiotics replenish good bacteria, helping restore the gut's microbial balance.

Beyond managing digestive side effects, probiotics may enhance antibiotic effectiveness. A study of 6,000 patients with H. pylori infections showed that combining probiotic supplementation with antibiotic therapy improved bacterial eradication rates by approximately 10%—a finding supported by later research. Due to this evidence, many healthcare providers recommend probiotics when prescribing antibiotics, with one important caveat: timing matters. Taking probiotics and antibiotics simultaneously can reduce the probiotic's effectiveness, so spacing them apart is critical.

Best timing for probiotics and antibiotics

Begin taking probiotics the same day you start your antibiotic course, maintaining a gap of at least two hours between doses. Dr. Hoberman clarifies: "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." Dosing varies by product, but adults typically take 10 to 20 billion colony-forming units daily, while children generally receive 5 to 10 billion CFUs per day. Continue your probiotic regimen for a minimum of one week after completing your antibiotic prescription.

Choosing the right probiotic with antibiotics

Pharmacy shelves stock numerous probiotic options, making selection confusing. Common bacterial strains include Lactobacillus, Saccharomyces boulardii, and Acidophilus. According to the American Family Physician, evaluate supplements using three criteria: diversity, dose, and delivery.

Strain diversity

Examine your probiotic's label to identify which strains it contains. Seek products containing five to ten distinct bacterial strains. Lactobacillus acidophilus and Bifidobacterium species are among the most extensively researched and have demonstrated effectiveness in stabilizing the microbiome compared to less-studied strains. If you're thinking about adding probiotics to your routine, ask your healthcare provider which strain diversity would suit your particular situation.

Dosage

Probiotic potency is measured in colony-forming units, abbreviated as CFUs. Most healthcare practitioners suggest a minimum dose of 10 billion CFUs daily.

Form of delivery

Probiotics are available in multiple forms—capsules, powders, gel caps, gummies, and liquids. The most suitable option for you depends on which form you tolerate and will actually take consistently. Your pharmacist can offer recommendations based on these three factors and your personal preferences.

Potential risks of probiotics with antibiotics

For most healthy individuals, combining probiotics and antibiotics carries minimal risk. However, research shows that immunocompromised patients may face an increased infection risk, and some people experience mild gastrointestinal effects such as gas, bloating, or constipation. Your healthcare provider can discuss whether probiotics are appropriate for your specific health status.

Timing remains essential even though probiotics do not directly interfere with antibiotics' bacterial-killing mechanisms. When taken simultaneously with antibiotics, probiotics lose effectiveness because the antibiotic kills the probiotic bacteria. Taking probiotics at least two hours before or after your antibiotic dose allows them to establish themselves without antibiotic interference and help restore the microbiome.

Opinions among healthcare professionals vary regarding routine probiotic prescription with antibiotics. This disagreement partly reflects gaps in research—while probiotics show clear benefit for preventing antibiotic-associated diarrhea, some systematic reviews found they did not substantially improve overall gut microbiome diversity following antibiotic therapy. Nonetheless, evidence supporting their role in diarrhea prevention remains solid. Discuss with your prescribing provider whether probiotics make sense for your situation and which formulations they recommend.

Dietary recommendations during antibiotic treatment

Supplementation alone is not the only strategy. Consuming whole foods containing probiotics and prebiotics strengthens your digestive system and offers an alternative or complement to capsules and powders. Prebiotics are indigestible fibers that pass through your system and nourish the probiotics already living in your gut, stimulating their growth and effectiveness. During antibiotic treatment, prioritizing both prebiotic and probiotic foods provides comprehensive support for your microbiome.

Incorporate these prebiotic-rich options to encourage beneficial bacteria such as Bifidobacteria and Lactobacillus: leafy bitter greens like dandelion, seaweed, and spinach; onions, garlic, and leeks; asparagus; bananas; apples; barley; oats; cocoa; flaxseeds; and roots including chicory root, jicama root, and Jerusalem artichoke.

Add probiotic-rich foods such as: fermented foods like raw, unpasteurized sauerkraut (pasteurization destroys the beneficial bacteria), tempeh, and kimchi; miso; yogurt and kefir with live and active cultures; buttermilk (traditional, not cultured); kombucha; and naturally fermented pickles (those pickled in salty brine, not vinegar-based varieties, retain probiotic activity).

Before significantly changing your diet during antibiotic therapy, consult your healthcare provider or pharmacist about potential food-drug interactions, particularly with fermented products or beverages that may affect your specific antibiotic's absorption or effectiveness.