Do Probiotics Cause Gas? What Science Says About This Common Side Effect

Expert reviewed by: Chelsea Jackle, MFN, RDN, LD

Overview

• Gas after probiotics is a common, temporary side effect as your gut adjusts to new bacteria.
• This mild discomfort may occur as microbes become active in your digestive system.
• Prebiotics from your probiotic supplement or diet can also affect gas production.
• Gas typically decreases within a few weeks as the microbiome adjusts. If symptoms persist, it may be worth consulting a healthcare provider.
• Everyone’s gut is different, so some people may experience more gas than others when starting probiotics.

Let’s talk about something many of us experience but rarely discuss: gas. If you’ve ever taken a probiotic and noticed some extra rumbling or bloating in the hours that follow, you’re not alone.

The connection between probiotics and temporary gas is common and well-documented. But before you give up on your beneficial bacteria, it’s worth learning about what’s actually happening in your gut when this happens.

Gas could mean that probiotics are doing their job—actively supporting a healthy and diverse gut microbiota. And fortunately, there are easy ways to minimize discomfort while still getting the benefits these helpful microbes provide.

This guide explains the science behind probiotic-related gas, why it happens, and simple, effective ways to make your probiotic experience more comfortable. Because let’s face it—you wanted to commit to gut health, not to becoming your home’s new natural gas provider.

The Science Behind Probiotic-Related Gas

When you add new bacterial strains to your gut via a probiotic, you’re essentially welcoming billions of tiny new residents to your intestinal neighborhood. And just like any new neighbors, they need time to settle in… and this sometimes means a little noise and inconvenience. (But fortunately, these new neighbors won’t accidentally block your car in the driveway.)

Why Gas Happens: The Microbial Moving Day

The human gut houses tens of trillions of bacterial cells. (Nearly as many as the total number of human cells in your entire body!) This complex ecosystem is delicately balanced, so even helpful disruptions can cause temporary discomfort while your microbiome adjusts.

1. Microbial Competition: When new probiotic strains are introduced, they can support changes in your gut microbiota. During this adjustment period, increased fermentation of fibers and the natural turnover of microbial communities may lead to temporary gas.¹   
2. Fermentation Effects: Gut bacteria ferment certain parts of your food (particularly fiber and prebiotics) in your gut, producing gases like hydrogen, methane, and carbon dioxide as byproducts.² This is a natural part of how probiotics help break down fiber and support digestion.
3. Enzymatic Differences: Certain probiotic strains produce helpful enzymes that support the digestion of nutrients, complementing the activity of your native gut bacteria. For example, Lactobacillus plantarum makes β-fructosidase, (an enzyme) which helps digest prebiotics like inulin.³ Bifidobacterium species, like B. lactis HN019, are able to break down complex carbohydrates, including oligosaccharides like FOS (fructooligosaccharides), GOS (galactooligosaccharides), and XOS (xylo-oligosaccharides).⁴  These digestive capabilities may temporarily increase gas production as your body adjusts to new metabolic pathways.
4. Microbial Turnover: As new probiotic bacteria settle in, changes in your existing gut microbiota can occur.^5,6 When certain bacteria decrease, this shift can lead to the release of byproducts, sometimes causing temporary gas.^2,7

This reshuffling is a normal part of improving your gut ecosystem, even though it might mean a temporarily gassy adjustment period. The amount of gas depends on your unique microbiome, the specific strains you’re taking, and even your most recent meals.

What Does Gas After Taking Probiotics Mean?

Gas after starting probiotics might actually be a sign that the microbes are becoming more active in your gut.⁸ 

When bacteria get busy fermenting fiber in your intestines, they make valuable compounds like short-chain fatty acids (SCFAs).^1,3  These SCFAs help strengthen your gut barrier, support immune function, and create an environment that discourages the growth of pathogenic bacteria.¹ The gas is simply a byproduct of this microbial activity.⁹

Think of it as construction noise during home renovation—annoying, yes, but a sign that changes are happening! Just like muscle soreness after a workout tells you your body is getting stronger, a bit of digestive gurgling can suggest your microbiome is actively acclimating.

Factors That Influence Whether You’ll Experience Gas

The good news is that not everyone experiences gas when taking probiotics. However, there are a couple things that may predict your likelihood of feeling bloated and gassy:

1. Your Initial Gut Health

A disrupted microbiome—whether from diet, medications, stress, or underlying conditions—may be more sensitive to changes when introducing probiotics, potentially leading to temporary gas and other digestive symptoms.⁸ It’s like rearranging a messy room—there’s going to be more chaos during the cleaning process.

If you have a health condition affecting the digestive system, such as Inflammatory Bowel Disease (IBD), it’s important to consult a healthcare provider before starting probiotics, as individual responses can vary.⁸

2. Dietary Patterns 

Your overall diet plays an important role in how your gut reacts to probiotics too. The types of foods you eat regularly can either support a smooth adjustment period or increase the likelihood of temporary gas.¹⁰ 

High-fiber foods like beans, whole grains, and certain vegetables contain prebiotics that feed your gut bacteria. While this is fantastic for long-term gut health, it can also lead to increased gas as your microbiome ferments these fibers.² (We’ve all experienced the aftermath of a bean burrito… right?)

On the flip side, prebiotics can come from more than just fiber. Foods rich in polyphenols––like pomegranate, green tea, and even chocolate––can help gut bacteria flourish without being fermented by them. (Translation: less gas, bloating, and farting.) ^9,11 

Think of polyphenols as your probiotics’ sophisticated dinner guests—they encourage good conversation (bacterial growth) without excessive noise (gas). Who knew your microbiome had such refined taste?

How to Minimize Gas While Taking Probiotics

If you’re experiencing the rumbles after taking your probiotic, try these science-backed strategies to make your gut’s adjustment period a little less… musical:

1. Start Low, Go Slow: Start with a lower dose, then gradually increase to the full dose over a few days. Think of it like trying spicy food—you wouldn’t immediately go for the “face-melting” hot sauce, right? While this method may keep bothersome gas in check, it should be considered a short-term approach––you may not experience the full beneficial effects if continued long-term. 
2. Choose Strains Wisely: If gas is persistent (we’re talking “can’t wear your fitted pants” persistent), consider switching to a different probiotic formulation, as tolerance can vary based on individual factors. Look for products that list specific strains (those letters and numbers after the name aren’t just for show—they tell you exactly which bacterial neighbors you’re inviting over.)
3. Choose Low-FODMAP-Friendly Prebiotics: “FODMAP” stands for Fermentable Oligosaccharides, Disaccharides, Monosaccharides, And Polyols. These are carbs that can be hard for some people to digest, and may cause gas and bloating when fermented by gut bacteria.²  Low-FODMAP diets are often recommended for people with irritable bowel syndrome, but products that contain FODMAP-friendly prebiotics may be gentler on the gut and reduce fermentation-related gas.²
4. Bedtime Workaround: It’s common for people to experiment with taking their probiotics at different times of the day to find what works best for their body and routine. Anecdotally, some people find taking them before bed reduces their awareness of minor digestive symptoms, as these adjustments can occur while they rest.

The Key Insight

That temporary tummy rumble after taking your probiotic isn’t necessarily a cause for alarm—it could be your microbial tenants moving in, rearranging the furniture, and setting up shop in your gut neighborhood.

For many people, this brief adjustment period is manageable and worth the benefits. However, if symptoms persist or become severe, it’s important to consult a healthcare provider.

By easing in slowly, selecting science-backed strains, and giving your body time to adjust, you can minimize the gas while still reaping the rewards of a healthier, more balanced microbiome.

Think of it like any home improvement project—there might be some noise and dust during construction, but the upgraded living space is absolutely worth the temporary inconvenience.

Frequently Asked Questions

How Can I Tell If Gas Is From Probiotics Or Something Else?

Probiotic-related gas can start shortly after taking a supplement and often improves within a few days to weeks. If your symptoms began around the same time as starting probiotics, they could be related.¹⁰ 

Can Prebiotics In My Probiotic Supplement Contribute To Gas?

Yes, prebiotics can contribute to gas for some people, particularly fibers like inulin and fructooligosaccharides (FOS).³  These fibers feed both native bacteria and probiotics, which can increase fermentation and gas production in some cases.^2,11 

Are There Any Probiotic Strains That Don’t Cause Gas?

While individual responses vary, research suggests that certain strains, including B. lactis HN019, L. acidophilus NCFM, and B. lactis Bi-07, are generally well-tolerated and may support digestive comfort. However, individual reactions to probiotics differ, and gas production can depend on many factors, including your unique gut microbiota and diet.^4,12  

Probiotics with a Low-FODMAP compatible prebiotic may be gentler on sensitive guts, as they are less likely to contribute to fermentation-related gas.² 

Remember: While probiotics can be invaluable for your health, they’re not a replacement for medical treatment. Always consult with a healthcare provider about your specific needs, especially if you have ongoing digestive concerns.