Can probiotics cause SIBO

Can Probiotics Cause SIBO (Small Intestinal Bacterial Overgrowth)?

Dr. Dimitar

Medically reviewed by: Dr. Dimitar Marinov, June 1, 2023

Probiotics are known as the “good gut bacteria” and are a common supplement for all ages. But if it delivers a concentrated dose of bacteria to your gut, is there a chance that it can actually cause SIBO (Small Intestinal Bacterial Overgrowth)? 

The answer is actually complicated. Studies on probiotics and SIBO have conflicting results. 

But I’ll break them down for you soon. Keep reading to find out.

Key Highlights
  • Some strains of probiotics are effective in treating chronic diarrhea caused by bacterial overgrowth while others may cause SIBO.
  • Disruptions in the normal conditions of the gut microbiota can lead to SIBO, which is often mistaken for irritable bowel syndrome (IBS).
  • Soil-based probiotics, such as Bacillus clausii, Bacillus coagulans, and Bacillus subtilis, may be effective in treating SIBO. Saccharomyces boulardii and Lactobacillus acidophilus and casei may also be helpful.
  • Click here for the BEST PRICE of our recommend probiotics supplement for SIBO

Is it possible that these differences are dependent on the probiotic strains used in the study?  If there are probiotics that can treat SIBO, which ones do we recommend? And if probiotics can cause SIBO, which ones should you avoid?

Let me explain each one below so you can choose the best options to avoid or even treat SIBO.

What Causes a SIBO Flare-Up?

SIBO - Small Intestinal Bacterial Overgrowth

Before anything else, it’s important to understand that our GI (gastrointestinal) tract contains a rich population of microorganisms. These gut microbiotas are important in digestion and keeping a healthy gut function.

The number of microbes increases the further down the tract you get. That means that there are fewer gut microbes in the stomach (especially because they can get killed by stomach acids) than in the small intestines.

The most number of gut microbes are in the large intestines.

However, certain disruptions in their normal conditions can lead to an overpopulation of bacteria in the small intestines. That’s SIBO.

When that happens, you might experience diarrhea, bloating, and stomach pain. Because of the similarities in their symptoms, SIBO is often mistaken for the more common IBS (irritable bowel syndrome).

What triggers SIBO and can probiotics cause the flare-up? Let me continue explaining it to you below.

Do Probiotics Cause SIBO? (what research says)

A 2020 review showed the two sides of the coin when it comes to the role of probiotics in both causing and managing SIBO.

Let me first discuss the negative effects as we answer this next question:

Can Probiotics Cause Bacterial Overgrowth?

The 2020 review mentioned above explained that some probiotics might cause bacterial overgrowth, which shows in the symptoms experienced or reported by the test subjects.

Probiotic cessation, followed by a course of antibiotics, resolved the patients’ gastrointestinal symptoms. 

High levels of methane or hydrogen in your breath could indicate SIBO.

In the same review, the researchers explain that subjects who used probiotics recently were more likely to have positive results for methane-positive LBT (lactulose breath testing) than hydrogen-positive testing.

These findings could mean that probiotic use can cause an overgrowth of methanogenic (methane predominant variant) bacteria that cause SIBO. These bacteria are often linked to constipation symptoms.

In a 2018 observational study linking brain fog, bloating, and gas to probiotic-induced SIBO, researchers found that stopping probiotics made the symptoms improve in the test subjects.

Can Too Many Probiotics Cause SIBO? (probiotic overdose)

This is another probiotic question that scientists can’t answer with a definite “yes” or “no.”

The complication stems from many different reasons.

First, the NIH (National Institutes of Health) explains that the common dose for probiotics is anywhere from 1 to 10 billion CFUs (colony-forming units), but some products offer as much as 50 billion CFUs. Still, the NIH points out that the higher values don’t always mean these probiotics are better.

But the higher number might also mean better, considering that probiotics need to be alive and able to survive your stomach acids for them to work in your intestines.

Surely, the higher their number, the better chances they might have for survival.

Well, that is also not the case. As you might have read in our previous articles, probiotic shelf life can be affected by heat, moisture, and other factors. 

It’s even possible that the active probiotics will all be dead by the time the supplement reaches your home (if the product wasn’t handled properly). Yet you’ll have no way of telling if that’s the case.

So, is 50 billion probiotics too much?

Since the FDA doesn’t regulate probiotics, there’s also no telling whether the dose printed on the label is correct.

So, you might be taking 50 billion CFUs of probiotics and declare that they don’t cause SIBO, based on your experience, yet that could be because the ones you took were already dead. Technically, you didn’t experience a probiotic overdose but you don’t know it.

The good news is that according to MemorialCare Medical Group’s Digestive Disease Center director and gastroenterologist Ashkan Farhadi, you can’t really “overdose” on probiotics the same way with other supplements or drugs.

Even if you take as many probiotics as you want, way above the 50 billion, it’s unlikely to cause serious medical risks, he added. It won’t put you at risk of death or dangerous complications, but you might experience severe discomfort with your upset stomach.

Doctors explain that there are actually trillions of different bacteria in your tummy. The addition of these probiotics might lead to SIBO, but it’s also possible that it won’t.

Still, a 2010 clinical trial actually showed that higher doses of probiotics (50 and 100 billion CFUs) Lactobacillus acidophilus CL1285 and Lactobacillus casei LBC80R can be more effective in alleviating antibiotic-associated diarrhea.

While that might be because antibiotics had killed off the normal gut flora of the test subjects, in the opposite situation as SIBO, it can be proof enough that 50 billion (or more) isn’t always a bad thing in probiotics.

Probiotics To Avoid: Which Ones Make SIBO Worse?

Lactobacillus and Bifidobacterium probiotic strains might be the culprits behind the overgrowth in SIBO, explains Amy Myers MD. So, it’s best to avoid probiotics with these strains if you are experiencing SIBO symptoms.

Evidence-Based: Probiotics Are Effective For SIBO 

Although studies on probiotics and SIBO do have conflicting results, there’s also some solid evidence that some strains are good for alleviating the symptoms of this uncomfortable condition.

This time, let’s dig deeper into the ones that might be good for dealing with bacterial overgrowth in your small intestines.

Probiotics For SIBO Treatment

Dr. Myers explains that soil-based probiotics can be a good treatment for SIBO, especially because they don’t get activated and thrive in the small intestines.

These probiotics come in a seed-like spore that knows to only activate when the conditions are just right. Their hardier shell helps them survive stomach acids and lets them go straight to the large intestines.

According to Dr. Myers, some studies showed that soil-based probiotics might significantly reduce the symptoms of IBS (irritable bowel syndrome). This is relevant to SIBO because as many as 80% of IBS patients might be dealing with SIBO, she added.

These are her recommended best soil-based probiotics to help treat SIBO:

  • Bacillus clausii – to modulate the immune response and produce certain chemicals that can help inhibit and kill pathogenic or bad bacteria
  • Bacillus coagulans – a well-studied potent immune stimulator that helps the good gut bacteria successfully colonize and thrive in your gut
  • Bacillus subtilis – to support gut repair, produces over 12 natural antibiotics, and ferment Vitamin K in your gut to promote growth and repair

Based on my research, these are strains that you can also add to Dr. Myer’s list of recommended probiotics for SIBO:

  • Saccharomyces boulardiiyeast strain that can help decrease hydrogen gas production and alleviate diarrhea without the risk of overgrowth in your small intestines
  • Lactobacillus acidophilus and casei – they’re shown in a 2014 study to be effective in treating chronic diarrhea related to bacterial overgrowth
  • VSL 3 – high-concentration probiotic preparation (with eight live species: Lactobacillus casei, Lactobacillus plantarum, Lactobacillus acidophilus, Lactobacillus delbrueckii subsp. bulgaricus, Bifidobacterium longum, Bifidobacterium breve, Bifidobacterium infantis, and Streptococcus salivarius subsp. thermophilus) shown in a 2003 study to be effective in the prevention and treatment of several diarrhea syndromes, including those due to SIBO
  • Lactobacillus reuteri – according to a 2021 review, this probiotic can prevent intestinal overgrowth by other bacteria and inhibit the production of proinflammatory cytokines to maintain a balanced gut environment
  • Lactobacillus rhamnosus – one of the probiotics shown to be effective in alleviating SIBO and clinical symptoms in another 2014 study
  • Bifidobacterium – several strains of this probiotic (Bifidobacterium bifidum, Bifidobacterium lactis, and Bifidobacterium longum) also showed similar results to Lactobacillus rhamnosus in the study mentioned above

Now, don’t be surprised that I listed Lactobacillus and Bifidobacterium probiotic strains above, even if these were listed by Dr. Myers as “not good” for SIBO.

That’s because, as you might have already noticed above, studies do show conflicting results between probiotics and SIBO.

In a 2016 case-control study, SIBO-positive cancer patients given Bifidobacterium triple viable capsules for four weeks showed reduced gastrointestinal symptoms.

Can SIBO Patients Take Probiotics?

There’s still a need for additional large-scale studies to better understand probiotics’ effects and risks on SIBO.

Considering the lack of clear consensus from doctors or researchers and the conflicting study results regarding probiotic use, it’s best not to take probiotics to treat SIBO without your doctor’s approval.

Once you get your doctor’s approval, finding the right probiotic might lead to some trial and error. You can find my recommendations below.

Recommendations: Probiotics For SIBO

For SIBO prevention and treatment, I covered a ton of the best probiotic supplements for SIBO treatment here. But let me share my top three choices with you below:

1. Yourbiology Gut+

A shelf-stable probiotic stored in amber bottles that don’t need to be refrigerated, Yourbiology Gut+ is my best choice for a potent probiotic that can be used by all genders.

I love that this probiotic supplement has plenty of features that give the best value for your money.

It contains 40 billion CFUs of Lactobacillus and Bifidobacterium strains:

  • Bifidobacterium lactis
  • Lactobacillus acidophilus
  • Lactobacillus paracasei
  • Lactobacillus plantarum
Probiology Gut+ bottle

Plus, the brand claims that these probiotic strains weren’t picked at random. Instead, they were chosen by the YourBiology team with help from top scientists and nutritionists so they can get the blend right for the best results.

YourBiology Gut+ can benefit SIBO by eliminating bloat, improving digestion, and strengthening immune support. It can even support a good mood.

Because it’s also free from gluten, dairy, and soy, this probiotic reduces the risks of experiencing the symptoms of lactose intolerance, including bloating, which can worsen SIBO.

At 40 billion CFUs, it’s several times the average 1-10 CFUs of other probiotics. While that might get you worried that these would just add to the overgrowth in your small intestines, there’s nothing to worry about.

YourBiology created Gut+ with patented MAKtrek Bipass Technology from brown seaweed to protect the probiotics in their journey down your gut, ensuring that they reach your large intestines without dying from stomach acids.

Traveling with a shield from stomach acids means that you get every bit of this probiotic supplement, right exactly where you need these live microorganisms.

2. Bauer Nutrition Biotics 8

A blend made especially for men, Bauer Nutrition Biotics 8 is good at eliminating excess gas and alleviating bloat symptoms in SIBO. Regularly taking this probiotic can make your tummy feel lighter and better.

It can even help calm digestion, strengthen your immunity, and boost your energy without making you feel bloated.

This blend features 10 carefully chosen probiotics that can also help reduce SIBO symptoms:

  • Lactobacillus rhamnosus
  • Lactobacillus acidophilus
  • Lactobacillus paracasei
  • Lactobacillus casei
  • Lactobacillus plantarum
  • Lactobacillus fermentum
  • Saccharomyces boulardii
  • Bifidobacterium bifidum
  • Bifidobacterium longum
  • Bifidobacterium breve

Bauer Nutrition Biotics 8 offers 20 billion CFUs per serving (three capsules).

3. FMF Soil-Based Probiotics By The Ruscio Institute LLC 

If you prefer soil-based probiotics, FMF Soil-Based Probiotics By The Ruscio Institute LLC can be a good pick. It contains genetically certified, lab-verified Bacillus coagulans and Bacillus subtilis strains that can help you deal with SIBO by:

  • Supporting your gut
  • Promoting a healthy inflammatory and immune response
  • Fighting harmful bugs and pathogens
  • Increasing diversity in your gut’s bacterial community

This product can alleviate SIBO symptoms like diarrhea and bloating.

FAQs on Probiotics and Small Intestinal Bacterial Overgrowth

Why Is SIBO Treatment With Probiotics Controversial?

Due to the marked differences and conflicts in study results about probiotics and SIBO treatment, some people in the scientific community view probiotic SIBO treatment as controversial.

After all, some studies do show that probiotics can cause or worsen SIBO symptoms.

The best thing to do is consult your doctor so they can recommend the right probiotic for your condition and symptoms.

Does Inulin Help SIBO?

Inulin is prebiotic, the food for probiotics. 

While prebiotics is good at helping jumpstart your probiotics supplements’ colonies in your gut, inulin supplementation might not be good if you have SIBO.

Since you’re dealing with an overgrowth of bacteria, providing them with more food is not really a good idea because that could actually help increase their numbers.

Can probiotics heal SIBO?

There is some evidence that probiotics may be helpful for SIBO, but the jury is still out. Some studies have shown that probiotics can help to decrease the amount of gas produced and the symptoms associated with SIBO. In contrast, other studies have shown that probiotics can actually make SIBO worse.


From our research above, some studies shows promising results of some probiotic strains possibly being effective in treating chronic diarrhea caused by bacterial overgrowth. Yet there are also other studies that show probiotics as the “bad guys” that could be behind the overgrowth.

So, the jury is still out on whether probiotics can cause SIBO.

Different studies have yielded conflicting results, and it may depend on the specific strains of probiotics used. If you’re experiencing any digestive problems, it’s best to consult with a healthcare professional before starting any new supplements, including probiotics.

Similar Posts

Leave a Reply

Your email address will not be published. Required fields are marked *