Antibiotics fight bacterial infections by killing or inhibiting the growth of harmful bacteria. Probiotics are live microorganisms, usually bacteria or yeasts, that confer a health benefit when administered adequately. The direct answer is yes, these two can be taken together, and current research suggests co-administration is often beneficial for supporting overall health during treatment.
The Impact of Antibiotics on Gut Health
Antibiotics cause “collateral damage” because they are not selective enough to target only disease-causing microbes. A broad-spectrum antibiotic indiscriminately eliminates significant populations of both pathogenic bacteria and the beneficial bacteria that make up the gut microbiome. This depletion of friendly microbes results in dysbiosis, an imbalance and reduction in the diversity of the intestinal flora.
The resulting microbial imbalance compromises the gut’s natural colonization resistance, which prevents the overgrowth of harmful organisms. This loss of protective function can lead to the proliferation of opportunistic pathogens, most notably Clostridioides difficile. The most common consequence of this disruption is Antibiotic-Associated Diarrhea (AAD), which affects approximately 5% to 35% of people taking antibiotics. AAD is defined as three or more loose stools per day occurring hours or up to eight weeks after starting the medication.
Essential Timing and Logistics for Co-Administration
The logistics of taking a probiotic alongside an antibiotic are crucial to ensuring the probiotic bacteria survive and provide benefit. The standard rule for co-administration is to separate the doses by a minimum of two hours. This separation prevents the antibiotic from immediately destroying the live microorganisms in the probiotic supplement, which would render the supplement ineffective. It does not matter which is taken first, only that a sufficient window of time is maintained between the two doses.
It is recommended to start the probiotic regimen on the first day you begin the antibiotic course, rather than waiting for gastrointestinal symptoms to appear. This proactive approach helps to maintain the gut microbial population from the outset, reducing the severity of dysbiosis. Continue taking the probiotic throughout the entire duration of the antibiotic treatment.
To maximize the opportunity for gut flora restoration, the probiotic regimen should be extended beyond the antibiotic course. Guidance suggests continuing the probiotic for at least one to four weeks after you have taken the last antibiotic dose. This continuation period assists the gut microbiome in recovering its natural balance and diversity. Consulting with a healthcare professional before starting any supplement is always a prudent step, particularly if you have an underlying immune condition.
Selecting the Most Effective Probiotic Strains
The efficacy of a probiotic is highly dependent on the specific strain, meaning that not all probiotic products will be equally effective at mitigating AAD. Clinical research points to a few specific strains that have demonstrated reliable success in preventing antibiotic side effects. These evidence-based options should be prioritized when selecting a supplement to take with your antibiotic.
One of the most strongly recommended organisms is the yeast Saccharomyces boulardii, which is naturally resistant to antibacterial medications because it is a fungus, not a bacterium. This strain is often administered at a dose of at least 10 billion Colony Forming Units (CFUs) per day for the prevention of AAD. Another highly effective strain is the bacterium Lactobacillus rhamnosus GG (LGG), which is widely studied and is effective in both adult and pediatric populations.
For both of these top strains, a dose of at least 5 to 10 billion CFUs daily is typically recommended to see a therapeutic effect in reducing AAD risk. Other beneficial strains may include specific members of the Lactobacillus and Bifidobacterium genera, but their effectiveness is not as consistent as S. boulardii or LGG. Choosing a product that contains a multi-strain combination that includes these high-efficacy strains can also be a beneficial approach.