Probiotics for Diarrhea: Can Probiotic Supplements Help with Diarrhea?

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Probiotics can help prevent and relieve diarrhea that occurs from antibiotic use, infections, traveling, and some underlying medical conditions in children and adults. Studies show that populating the digestive tract with certain probiotic strains can help fight off infections that lead to diarrhea or replenish what may have been lost through illness or use of medications.

Most of us can expect to experience a bout of diarrhea about once a year, while most otherwise healthy children get it twice that often, on average. Although diarrhea is common, it’s certainly not simple. Its causes can be complicated, and its effects range from inconvenient to devastating.

Research is focusing on how probiotics—live microorganisms that inhabit the gut—can help reduce the severity of diarrhea or prevent it from occurring in the first place. Studies are promising, and probiotics are now regularly recommended to help people of all ages get relief from both acute and chronic diarrhea.

How Probiotics May Prevent or Relieve Diarrhea

At least four major underlying causes of diarrhea include:

  • Foreign pathogens (germs), including notable ones like Salmonella, E. coli, Vibrio cholerae, and Clostridium difficile
  • Medications and medical interventions such as antibiotics and radiation therapy
  • Intestinal inflammation
  • Physical and emotional stress

To understand what probiotics do to help, we first need to wrap our heads around how they support our digestive health.

By now, we know probiotics are the “good bacteria” that live in and on the body, predominantly in the gut (i.e., the small and large intestines), and that we should incorporate them into our diet and wellness routines.

A healthy gut populated with beneficial microorganisms is a first line of defense against the factors that cause diarrhea.

Here’s what we know:

A healthy intestinal flora can stop harmful germs from proliferating in the body, according to researchers. One reason is that many probiotic strains have antibacterial effects that can inhibit the growth of pathogens like Salmonella, E. coli, Vibrio cholerae, and C. difficile.

An ideal microbiome also contributes to a healthy intestinal mucosa. This means germs are less likely to stick to the lining of the intestine or make their way through the lining into other parts of the body.

And since there’s a finite amount of space in anyone’s digestive tract, the population of good bacteria has a chance to crowd out the bad, leaving them without space and nutrients to thrive.

In other words, the makeup of your gut microbiome determines how well your immune system functions.
Not only does the intestinal microbiome fine-tune the immune system, but it also participates in a complicated messaging system with the brain that controls how quickly food moves through your digestive system.

The strains that populate your gut interact with the food you eat, the germs you encounter, and the chemicals your own body produces to regulate what’s known as “gut transit time” (GTT). For example, when you’re constipated, your GTT is too slow. In the case of diarrhea, it’s too fast. Constipation and diarrhea are normal from time to time, but a gut populated with mostly beneficial bacteria helps keep the speed of the digestive system regular.

By taking probiotic supplements preventatively, like before and during a round of antibiotics, for example, you could improve your chances of avoiding stomach upset. If the opportunity for prevention has passed and diarrhea has already set in for any reason, there is a good chance probiotics can help relieve the symptoms sooner.

Types of Diarrhea that May be Helped by Probiotic Use


Probiotic bacteria may help with:

  • Antibiotic-associated diarrhea
  • Traveler's diarrhea
  • Infectious diarrhea
  • Diarrhea in Children

Antibiotic-Associated Diarrhea

Sometimes there’s just no getting around the need to take antibiotics. They save lives by obliterating bacteria—both bad and good. Even the beneficial colonies of bacteria in your gut get wiped out, often causing an imbalance in your microbiome and a cluster of unwanted digestive issues.

In as quickly as 48 hours after beginning a course of antibiotics, symptoms like stomach ache, nausea, bloating, and antibiotic-associated diarrhea (AAD) can start. You might feel “normal” after stopping one or multiple rounds of antibiotics, and it’s true that the microbiome can rehabilitate itself on its own in some healthy people.

For others, though, antibiotics can permanently reduce the number and species of beneficial microorganisms in the body. An imbalanced gut microbiome can put you at risk for secondary infections and other health issues, including mood imbalance, brain fog, and allergies.

The good news is taking probiotics while also taking antibiotics can help alleviate these symptoms, including diarrhea, and help build back a robust microbiome.

Research backs this up. In a meta-analysis of 17 studies involving over 3,000 antibiotic users, 18% of those who did not supplement with probiotics experienced AAD. That number dropped to 8% among the study participants who did supplement with probiotics.

Our Omni-Biotic AB 10 probiotic was tested in multiple clinical studies with patients who were taking antibiotics. In one study, participants who took the antibiotic amoxicillin together with Omni-Biotic AB 10 showed a 31% reduction in AAD. In a second study, the incidence rate of AAD was reduced to less than 1% in patients who took Omni-Biotic AB 10 alongside their antibiotic treatment, compared to AAD rates of 25-49% without probiotic supplementation.

Pro tip: Unless the product you’re using directs otherwise, try to take your probiotic and antibiotic an hour apart to give the probiotic a chance to work.


Traveler's Diarrhea

Traveler’s diarrhea (TD) happens when you consume food or water contaminated with harmful germs while traveling. It affects 30-70% of travelers, depending on the location and time of year.

Bacteria, most commonly E. coli, Campylobacter jejuni, Shigella spp., and Salmonella spp., are to blame for 80-90% of cases of TD. Viruses and parasites can also cause it.

Antibiotics used to be prescribed to travelers as a means of preventing TD. The problem is some bacteria are becoming resistant to antibiotics, and the drugs themselves can lead to diarrhea. As a result, researchers are looking for alternative ways to prepare the body for what it might encounter during travel.

Testing probiotics as a way to prevent and/or treat TD hasn’t been easy. An article in The Journal of Nutrition explains:

“Investigations of the effect of probiotic bacteria on traveler’s diarrhea in the past showed inconsistent results because of differences between probiotic strains, the traveled countries, the local microflora, eating habits of the travelers, or the time point (before or during travel) and means…of administering the probiotic. Whereas some studies revealed fewer or shorter episodes of diarrhea in subjects consuming the probiotic, others found no such effect.”

That said, some studies are promising. They’ve found probiotic strains Bifidobacterium bifidum, Lactobacillus acidophilus, and Saccharomyces boulardii can prime the digestive system and help prevent TD.

Infectious Diarrhea

Infectious diarrhea is just what it sounds like—diarrhea that’s caused by and spreads through an infectious bacteria, virus, or parasite.

These harmful microbes cause abdominal pain and inflammation in the intestine, which, if left untreated, can lead to dehydration, colitis, and death. Infection usually leads to acute diarrhea (lasting under 14 days) but can become chronic.

Some notable germs you might recognize include:

  • E. Coli
  • V. cholerae (“cholera”)
  • C. difficile
  • Rotavirus
  • Salmonella

These are also many of the pathogens implicated in traveler’s diarrhea.

Rotavirus, in particular, is prevalent and dangerous in developing countries, affecting the most vulnerable, including children. Luckily, probiotics help. Experts believe they help build up the immune system to fight off the infection. Probiotics can also shorten the duration of infection.

Infectious diarrhea isn’t just an issue in developing countries. Around 30% of the population of developed countries is infected every year, and it usually spreads through contaminated food.

Then there’s “C. diff” (the name given to the infection caused by Clostridium difficile). It warrants special mention because it’s becoming increasingly common and hard to treat. About half a million cases of this infection occur in the U.S. every year alone. At one time, the population at risk was limited to the elderly or those in hospitals or long-term care facilities. Now, it’s infecting younger, healthier people.

One of the main risk factors for C. diff is antibiotic use because, as we know, the gut loses the beneficial organisms it needs to fight off infections. The irony? Antibiotics are also the treatment. This has led to the emergence of an antibiotic-resistant strain of C. diff that’s hard to control.

If C. diff patients can’t be treated with antibiotics anymore, what about probiotics? Research is emerging. According to studies, the use of probiotics, including lactobacillus strains and S. boulardii, may help prevent it, especially in high-risk populations. The probiotic strains in the Omni-Biotic AB 10 formulation have the ability to fight the harmful C. diff while also helping to degrade the C. diff toxins. When tested in a small observational study, patients taking Omni-Biotic AB 10 saw a significant reduction in C. diff infection.


Diarrhea in Children

Diarrhea in children can be dangerous. While it’s normal for kids to experience it on occasion, loose stools and loss of fluids in very young children can quickly lead to dehydration and loss of electrolytes. This is what makes infectious diarrheal diseases like rotavirus especially perilous.

Children can get diarrhea for the same reasons as adults—infection, underlying medical conditions, and medications, for example. Their microbiomes are building, and their young immune systems are modulating.

Childhood is the perfect time to set the foundation—through diet, lifestyle habits, and supplements if needed—to establish healthy gut microbiota.

The Journal of Nutrition notes:

“Young children may be particularly responsive to probiotics because of the immaturity of their immune system and the greater simplicity of their intestinal microflora compared with that of adults.”

Kids benefit from different strains than adults, so it’s important to find a product that’s suitable for the pediatric population.

A systematic review of 63 randomized controlled trials involving over 8,000 infants and children found probiotics to be useful for reducing the duration of infectious diarrhea by about 25 hours. Single- and multi-strain probiotics were tested.

The outcome? Probiotic supplements and foods containing Lactobacillus rhamnosus, Saccharomyces boulardii, Bifidobacterium lactis, and L. casei were shown to be effective in reducing illness in children.

So whether your child is experiencing diarrhea from something as simple as a “stomach bug” or a complicated issue like food sensitivity, probiotics can help.

Chronic Diarrhea

How long does diarrhea need to last to be considered a long-term problem? After 14 days, according to the World Health Organization. Having loose, watery stools that last 2-4 weeks is considered chronic diarrhea.

Besides infection from pathogens, underlying health issues like irritable bowel syndrome (IBS) and/or medications can cause it. Uncovering the “why” behind persistent diarrhea is important for avoiding complications or a worsening of whatever’s causing it.

Thanks to the health benefits of probiotics, including their ability to regulate the speed at which food moves through your digestive system, they can be a useful tool for controlling chronic diarrhea. Incorporating prebiotic foods or supplements into your diet can amplify this effect.

Can Probiotics Cause Diarrhea? Possible Side Effects

Every body is different. So even though all signs point to probiotics’ benefits in normalizing bowel function, there are some people who might experience diarrhea because of them. Most don’t experience a worsening of their diarrhea, however.

When first starting a probiotic, the gut flora rebalances and purges the undesirable organisms in a common process called "die off". This can temporarily exacerbate GI symptoms, including diarrhea, before beginning to improve them.

If your digestive symptoms persist after more than a few days, check with a healthcare provider who has experience recommending probioticsAdjusting your dose, product, or routine could help reduce gastrointestinal distress.

As a reminder, if you’re very ill or want to give a probiotic to a sick child, always check with a doctor first.

What are the Best Probiotic Strains for Diarrhea?

Supplementation with different probiotics ensures you’re replenishing (or introducing!) microbial diversity to your gut. A few strains stand out in clinical trials among the rest for preventing and reducing the duration of diarrhea, particularly strains of lactic acid bacteria. Beneficial strains include:

  • Bifidobacterium lactis
  • Lactobacillus acidophilus
  • Lactobacillus casei
  • Lactobacillus reuteri
  • Lactobacillus rhamnosus
  • Saccharomyces boulardii

When choosing a probiotic supplement, it’s important to consider which strains are used, but sometimes the right types of bacteria are not enough. You should also consider the research, ingredients, and especially the effectiveness of the delivery mechanism to maximize your benefits.



The effects of probiotic foods and dietary supplements reduce the incidence and severity of many of the most common types of diarrhea. Research shows they’re effective for the prevention of antibiotic-associated diarrhea and loose stool caused by harmful infectious agents. Probiotic products can help normalize bowel movements and modulate the immune system.

Omni-Biotic AB 10 was specifically formulated to help restore and maintain the gut flora and to support the gut microbiome during and after antibiotic intake and pathogen infection. This specific formulation has been tested in multiple clinical studies, which show a significant reduction in AAD and C.diff.

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