Understanding how probiotics and antibiotics can work together

Antibiotics are powerful drugs that are used to treat bacterial infections. In many instances, antibiotics may save lives. However, as with most medications, antibiotics can have a wide range of adverse effects - particularly on the gut microbiome.

Probiotics are beneficial bacteria that can support the health of the gut microbiome and restore the balance of ‘good’ bacteria. This blog post will discuss how probiotics and antibiotics work and how probiotics can promote overall health.

What are antibiotics?

Antibiotics are medications that target and kill certain types of bacteria. They are used to treat and prevent bacterial infections. Specifically, antibiotics work by destroying the bacterial cell - either by preventing the cell from reproducing or by altering a necessary cellular process within the cell.¹

However, because antibiotics do not distinguish between ‘good’ and ‘bad’ bacteria, they can have several negative impacts on the gut microbiome.

Broad‐spectrum antibiotics reduce gut microbiota diversity, as well as eradicate beneficial microbes.² Some research shows antibiotics can change microbial composition for up to 12 weeks after treatment is completed and that microbial composition remains unrestored, potentially allowing antibiotic‐resistant strains to develop.³

These effects can have a negative impact on numerous body systems, including immune function and metabolism, among others.

What are probiotics?

Probiotics are defined as live nonpathogenic microorganisms that can be taken to improve the balance of the gut microbiota, particularly in the gastrointestinal tract. ⁴ Major species of probiotics include lactic acid bacteria, such as Lactobacillus and Bifidobacterium species, and Saccharomyces boulardii yeast. These are available as dietary supplements and in foods.

Probiotics work in many ways to promote gut health, including:

• Colonizing and normalizing the microbial community of the intestines
• Competing with pathogens and production of bacterial species
• Providing important enzymes and production of fatty acids
• Supporting immune system function
• Interacting with the brain-gut axis

Antibiotics are shown to reduce the diversity of gut microbiota, which can increase the prevalence of harmful bacteria. In adults, certain combinations of antibiotics have been found to result in an increase of Enterobacteriaceae (a large family of Gram-negative bacteria) and other pathogens, along with a decrease in “good” bacteria such as Bifidobacterium and other species that produce butyrate (a beneficial short-chain fatty acid that have numerous roles in the gastrointestinal tract).⁵

Antibiotics can also disrupt the balance between different gut microbiota species, leading to an overgrowth of opportunistic pathogens such as C. difficile.

These changes in gut bacteria can increase susceptibility to further colonization by harmful species and also lead to the development of bacterial antibiotic resistance.

Health professionals are often asked, “Can you take antibiotics and probiotics at the same time?” Yes, you can - and you should.

Probiotics support the gut in several ways. Studies show their beneficial effects include lowering intestinal pH, decreasing the invasion and colonization of pathogenic bacteria, and boosting the immune response.⁶

It’s important to note that different probiotic species may have different mechanisms.

A large meta-analysis found that probiotics have a protective effect⁷ against diarrhea when taken with antibiotics. Data from 17 studies, including a total of 3,631 patients of all ages, found that taking probiotics and antibiotics together can reduce the risk of antibiotic-associated diarrhea by 51%.⁸ Probiotics also reduce damage⁹ caused by antibiotics to the gut microbiome.

Probiotic supplementation can increase the production of short-chain fatty acids (SCFA), which have many important roles in gut health. SCFAs are produced by probiotics from prebiotic dietary fibers. Their roles include regulating the pH of the gut to inhibit pathogens, controlling appetite, supporting other probiotic bacteria, providing energy for colon cells, maintaining the gut lining, combating inflammation, and supporting the immune system.¹⁰

Probiotics can also treat several gastrointestinal conditions by modifying the composition and/or activity of the gut microbiota. Specific strains have been shown to reduce symptoms associated with inflammatory bowel disease, irritable syndrome, and other GI disorders, as well as improving bowel regularity and stool health.¹¹

Probiotic supplements containing lactic acid bacteria and Bifidobacterium are effective in supporting beneficial microbes in the small intestine, which is where nutrients are absorbed into the bloodstream. These strains of probiotics also help to improve intestinal barrier integrity and reduce the incidence of diseases in the small intestine, which can interfere with nutrient absorption. Researchers suggest that strain-specific probiotics may be a natural and effective approach to restoring intestinal barrier integrity for better nutrient absorption and overall health.¹²

Different types of probiotics and their benefits. The main strains of probiotics that are most often used in probiotic supplements are Lactobacillus, Bifidobacterium, Saccharomyces, Streptococcus, Enterococcus, Escherichia, and Bacillus.

Production of lactic acid and other metabolites

• Colonize the digestive tract, the mouth, and the vagina
• Improve digestion of lactose and micronutrients
• Supports immune function
• Reduce antibiotic-associated diarrhea
• May help prevent or improve eczema in children, lower cholesterol levels, and assist with weight management

• Assist lactose digestion
• Help prevent or reduce diarrhea
• Reduce symptoms of irritable bowel syndrome (IBS)
• Improve bowel regularity
• Support intestinal integrity

• Naturally resistant to antibiotics¹⁶
• Help prevent and treat diarrhea (in children, antibiotic-associated diarrhea, and traveler’s diarrhea)
• Treating Helicobacter pylori infections
• Treating inflammatory bowel disease

Recommendations about probiotic and antibiotic timing may vary, but generally, it’s best to take a probiotic at least two hours before or after taking an antibiotic. This is usually enough time for the probiotic to reach the digestive tract uninhibited by the antibiotic.

Taking probiotics while you eat is also recommended, as food increases the pH of the stomach, thus reducing the acidity that can harm the probiotic bacteria. 

Not all probiotic supplements are effective, which is why it’s important to know what to look for.

The efficacy of a probiotic supplement comes down to a number of factors: potency, certification, ingredients, and manufacturing.

Potency: A high CFU count is recommended as not all bacteria (excluding Bacillus species) will survive the passage through to the small intestine. Researchers suggest a minimum of 1 million viable CFUs per gram are necessary to provide benefits.

Certification: The product should be tested and approved by credible third parties.

Ingredients: Supplements should be free of artificial additives or fillers.

Packaging: The supplement should be packaged to maintain viability and tested by independent parties.

The best probiotic for antibiotic diarrhea and for taking along with or after a course of antibiotics is RestorFlora™. This unique formula contains Saccharomyces boulardii and two Bacillus strains, all of which are shown to improve digestive function, support bowel regularity, and help maintain overall gut health. RestorFlora™ is also designed to assist with healthy detoxification and immune function.

Spore-based probiotic strains are among the most effective probiotic supplements. Spore-based probiotics are made up of endospores that encapsulate the strains, making them highly resistant to stomach acid. This allows more of the beneficial bacteria to be delivered to the small intestine, where they can begin colonizing the gut.

Mega SporeBiotic™ is a spore-based, broad-spectrum probiotic that contains a blend of five Bacillus spores. Unlike many other probiotics, Mega SporeBiotic effectively reconditions the gut with spores that survive the harsh gastrointestinal environment, promoting microbial diversity and healthy gut flora. Germination can occur within just three hours of ingestion. Both RestorFlora™ and Mega SporeBiotic™ also dairy-free, soy-free, gluten-free, and non-GMO.

Antibiotic use may deplete the gut of valuable microbes, which must be restored to maintain good health. A quality probiotic supplement may be an effective means of replenishing gut microbial diversity in the intestines and supporting gut health both during and after antibiotics. Take care to choose a supplement with a clinically researched formula and the appropriate certifications.